Suspension Upgrades

Last updated: June 07, 2000


Suspension Diagram w/ Part Numbers 1

Suspension Diagram w/ Part Numbers 2

The two preceding diagrams courtesy of Tony (

The next photo shows the front suspension, steering rack, anti-sway bar, etc.:

Front Suspension Photo

The next photo shows the front suspension, in the first photo, and then the rear in the second:

Rear Suspension Photo

The next photo shows a rolling chassis, with the powerplant frmae (PPF) in yellow in the center of the chassis:

Rolling Chassis Photo

Daily Driver Suspension Upgrades

date: 03/22/2002 02:05 PM

/*  Caution - Opinionated Content Follows  */
/*  Authors of identified Opinion are protected against flaming by Federal law.  */

There is an amazing amount of information available for the FD as to various suspension products, and about techniques of suspension tuning. I've read a lot on general topic over the years, and for the last two years specifically about the FD, but I believe that almost all of the information available on the web has two flaws: the author rarely states what he is tuning for or how he plans to use the car, and, the answer to the question is most often "track" or racing of some sort.

(Editor's note: most of the rest of the information in the Suspension section on this site is oriented toward racing. --Steve>

This is an attempt to document a balanced set of FD suspension tweaks for the non-racer, non-dragster daily-driver FD, like mine, and to make recommendations for a well-balanced sports car suitable for part-time real-life use on twisty roads.

My car is an automatic (bought it for a fun commuter), and is presently my only vehicle. It might spend a day or two of its future life on the track, but the other 99.9% of its use will be on city and suburban streets, highways, and (the fun part) local county roads, where I often go and play for a few hours.

My interest is in keeping the ride comfortable, while enhancing the handling of an already great car, with the peak handling requirements directed toward poorly-maintained coastal county mountain roads - potholes, ripples, and hairpins abound.

With that as a forward, I'd like to recommend a series of inexpensive mods that can make the FD a much tighter handler, faster thru the corners in my stated environment, and a lot more predictable, and perhaps even improving the ride and comfort for daily-driver use. I hope this missal helps someone looking at the same decisions I was two years ago, after I bought my car.

Three areas on which I'll make recommendations from personal experience: tires/wheels, springs/shocks, and swaybars and other minor suspension stuff.

  1. Wheels and Tires: IMHO, changing the wheel and tire sizes on this car is a move in the wrong direction. (Note: for my purpose, as stated above.) The stock wheel and tire size is a great compromise for street use. If you use larger wheels, you have less rubber between you and the road, and higher unsprung weight, and the ride will be suffer. You will also go slower on my "track", as described above, because a heavier or wider wheel/tire combination won't give as good traction or acceleration on the pot-holed, real-life county roads that are my target. Save your money.

    For tire pressures for the street, I use 31 lbs. most of the time, on stock-size tires, which softens the ride quite a bit on highway dots and such. 2-3 lbs. over stock keeps the tires on the rims when I'm out carving hairpins, without making the tires too bouncy.

  2. Springs/shocks: The stock springs are a little soft for best handling (and the stock shocks are a bit stiff). Unfortunately, there are no good alternative springs available for my purposes, as all aftermarket springs lower the car too much for the real-life roads that I drive on. My car bottoms out on certain spots in certain roads with the stock springs, so lowering is not in the picture. You could buy a completely adjustable coilover suspension and specify the spring rates and ride height to suit yourself, but that is a lot of money for a daily driver...

    The stock shocks, on the other hand, are worth replacing, with a strong preference for an adjustable shock. I have Koni Sports, and have spent more than a year fiddling with settings, only to conclude that 1/8 or 2/8 of a turn harder than softest, at both front and rear, works best for my roads. Any firmer, and the car simply skitters around too much on bumpy curves. The Konis are softer than stock in compression, which softens the ride somewhat on bumps - again I find that 1/8 turn gives a great combination of handling and ride 90% of the time. For interstate highway cruising, I set the Konis to softest.

  3. Swaybars/mountings/Other: There are a lot of "upgrade" anti-roll bars and mounts available. Almost all of them are designed for the track, and work best with hard springs and shocks. The sole exception to this, in my opinion, is the Addco front bar, which, at 25% firmer than stock, at least won't foul up the balance of handling too much. (BTW, all of the mods described below will work with the Addco bar.)

    Otherwise, for my stated purposes, don't waste your money on fancy swaybars. My recommendation is to spend less than $200 for small parts, and optimize the stock swaybars. This consists mainly of taking a lot of slop out of the mountings and bushings, which gets rid of the sloppy-across-the-transition feeling when you enter a turn or change direction. Steering will be much more immediate and more precise.

    • Assuming that your stock swaybar mounts aren't cracked, get a Racing Beat swaybar mount reinforcement brace for $75. If your mounts are cracked, repair/replace them first.

    • Get Summit Racing replacement front swaybar bushings and u-mounts for $20. These are urethane bushings in wider more robust mounts. Instructions at

    • Replace the stock front bar end-links with solid rod-ends, $70 from Mazdatrix. Instructions at When you do this mod, instead of placing half of the washers inside the rod-end and half outside as shown in the pictures, place all of the washers outside the rod-end. This shortens the effective length of the bar arm, and thus stiffens the front bar by about 7-8%, which is about right. Slide the Summit Racing bushings all the way forward to keep the rod-end vertical.

    • Finally, stiffen the rear swaybar mount. Get two replacement rubber bushings for it from Mazda for around $20 - the originals are probably worn anyway. Note that there is about 1/2" of very compressible rubber between the bar and the body of the car. Get a small piece of 3/8" thick plastic - plexiglas is available in black, and easy to work. Cut two 1" squares, and file flat notches in opposite sides so that it can fit into the swaybar u-mount, and matches the shape of the flat side of the rubber bushings. Take a sharp knife, lube the blade with dish soap, and cut off 3/8" of an inch of the rubber from the flat side of the bushing. Re-install the u-mount with the plastic piece closest to the car body, replacing the compressible rubber you cut away. This take quite a bit of slop out of the rear bar mounting, to balance the changes at the front.

  4. In the "Other" category, get a front strut brace. This keeps the car from flexing on bumpy corners, and keeps you going where you point it. There is no point but cosmetics in spending much money on this - for our purposes, any brace works as well as any other.

  5. And one final Other recommendation - replace the stock rear toe-links with the M2 version for under $200. The stock car has rubber in these bushings, which lets the rear wheels toe in under braking - a strategem to protect unskilled drivers from themselves, as it makes the car try to go straight. I came to seriously dislike the feeling that someone had grabbed the steering wheel when I hit the brakes hard. The M2 toe links make clean launches easier, improve corner entry quite a bit (since you aren't fighting dynamic toe in), and allow for much better control of the tail end under power.

So that's my 3 cents worth. I love the way my car rides and handles now - for my purposes it's a whole lot better than stock for less than a whole lot of money.

I don't plan to replace the other bushings on my car with anything but stock, but I do have one further suspension upgrade planned to my car - an on-order torque-brace from the group buy on the RX-7 forum. If it works as I hope, it will remove a lot of drivetrain windup and lash, make the shifting of my automatic tranny less jerky, and allow for more control of the tail-end with the throttle. This remains to be seen, but I'm looking forward to finding out...

John Ames' Setup

From: (Kevin Wyum)
Date: Sun, 26 May 1996 02:01:13 -0500 (CDT)

On this topic I did finally get in touch with John Ames who ran in the One Lap last year. As somebody stated he was solo II champ for 2 years straight in his R1. He sold it now though and got an SLP Firebird. Said he wanted to try something new since he beat everybody with his RX already. I any case I trust this guys opinions with respect to suspension. It turns out his opinion of the best things to use which he did were the same as what I just finished putting in my car over the weekend. He ran the same tires, shocks, springs etc. So this is what is being used John. GAB super R 8 way adjustable shocks, $207 each through Mazda comp. BTW the Tokiko adjustables are only like $110 each. Eibach protrack springs and front and rear sway bars. I 've only had it out for a couple hundred miles like this but,, WOW they do make quite a difference and mine was an R1.


Ed.'s note: You will probably buy the springs as a set with coil-overs, and the shop you buy from will need to match the springs and shock valving rates. This Spring section is intended more for upgrading the springs on the stock shocks or similar replacements. --Steve



From: Glen" (
Date: 08/02/2002 04:04 PM

Shock make / model                          Front Spring Rate kg/mm (lb/in)      Rear Spring Rate kg/mm (lb/in)

Apexi 2000 double rate                      12 ~ 8 (671 ~ 447)                   12 ~ 8 (671 ~ 447)
Apexi T-Max Type 1 '96, Ride height>> -25mm 7.2 (402)                            4.7 (263)
Apexi Type 2 1996                            11 (615)                            7.2 (402)
Cusco                                         8 (447)                              6 (335)
HKS                                           7 (391)                              6 (335)
JIC SA-2                                     16 (894)                             12 (671)
JIC SF-2                                     16 (894)                             12 (671) 
Mazda FD3S 1992 Stock                       4.8 (268)                            3.6 (201)
Mazdaspeed Eibach, Ride height adjustable   7.3 ~ 5 (408 ~ 279)                  5.1 ~ 4.05 (285 ~ 226)
Mazdaspeed Eibach, Ride height>> -25mm      6.9 (386)                            5.1 (285)
Quantum Nova                                            18 (1006)                            16 (894)
Quantum spg                                             16 (894)                             16 (894)
Quantum swift                                           20 (1118)                            20 (1118)
Racing Gear                                           11.3 (630)                            7.9 (440)
Racing gear                                           10 (559)                                8 (447)
Tanabe Super H, Ride height>> -13mm front -20mm rear  5.4 (302)                             4.7 (263)
Tein HA                                               14 ~ 10 (782 ~ 559)                  12 ~ 8 (671 ~ 447)
Trust GREX sports, Ride height>> -25mm                4.8 (268)                             3.6 (201)
kg/mm DR21                                            7.4 ~ 5.6 (414 ~ 313)                5.8 ~ 4.4 (324 ~ 246)

I use Quantum swift 1120 / 1120 lb/in on the street and they aren't as harsh as people make out. Don't get me wrong, they are stiff but once your a moving they ride smooth, no jarring...and out roads are shocking!


Racing Beat

Date: Tue, 22 Jul 1997 18:29:05 -0700
From: (FD3S Power)

The Racing Beat springs are linear springs lowers approximately 1.25 inch all-around. It's, in fact, one of the spring sets that lower the most (other than H&Rs and STs). With these springs, you get great feedback in the turns & bumps. There is also less dive compared to the stock springs. They're also a great deal (price-wise) compared to some of the other brands available.


Date: Thu, 12 Mar 1998 19:19:39 -0500
From: "David Ieroncig"

I did the RB spring thing and I don't regret it. Lowers the car nicely (more in the back) and doesn't degrade the ride that much. However it does... by about as much as the quoted stiffness increase (seat of the pants wise) 8-10%. I did feel the need to upgrade to stiffer shocks though. Maybe it's just because my base shocks had 30 000 miles on them I dunno... I put R1 shocks on now and I feel like there's less bobbing up and down. Not a neccessity though... as the pseudo racer that I am, I don't mind the extra stiffness.

I would like to add... a wise word that I recieved from fellow list member Tom Gandey last year... "a good alignment will do more for your car's handling than doing just the springs".



Date: Sun, 5 Oct 1997 18:34:00 -0700
From: (Chris P Sychlovy)

>I have a simple question to ask. What are the
>stock spring rates on a Mazda RX-7 R1?

Not as simple as you think. In my quest for springs, the only reasonable answer came from an Eibach tech. All '93s, including the R1, had the same springs, 281 lb/in front, 200 lb/in rear.


Date: Sun, 5 Oct 1997 22:42:12 -0500
From: "David Ieroncig"

Yamaguchi's bookstates differently...

Spring rate is to be the same all around... 106 lb/in.


Date: Mon, 6 Oct 1997 07:28:46 -0400
From: "John Levy"

I think Yamaguchi is referring to wheel rate rather than spring rate. I measured the stock springs at 155 lb/in in front and 120 lb/in in the rear.

Date: Mon, 11 May 1998 22:15:40 -0400
From: "John Levy"

My method of measuring used a simply scale set on a press that I could move continuously. By taking a reading on the scale with tension on the spring and then moving it one inch and taking another reading I established the lbs/in.

This method should be gross compared with the intergraph tester.

I would be more than happy to calculate the wheel rates if someone would send me the diameter of the stock front and rear sway bars, as well as their arm lengths measured to the bolt hole.


Date: Mon, 11 May 1998 11:49:38 +0200
From: "Bernd Kluesener"

I don't know what John Levy measured and how he did it. He claims the spring rates for a 93 R1 to be 150 lbs/in front and 120 lbs/in rear.

Using my Intergraph digital spring tester, I found the following:

R1 front 279 lbs/in
R1 rear 198 lbs/in
R2 front 274 lbs/in
R2 rear 198 lbs/in

Given the suspension geometry of the RX7, this is also pretty consistent with the 106 lbs/in wheel spring rate Yamaguchi claims in his book.


Date: Tue, 12 May 1998 10:52:21 +0200
From: "Bernd Kluesener"

it was not my intention to question Your readings. However, the simple scale on a press method has its pitfalls as can be seen from the following formula:

	Spring Rate	=	F/S
			=	Gd**4/8ND**3   (** is ASCII for exponentiation)


	F = spring force in pounds
	S = spring deflection in inches
	G = torsional modulus of the material (Steel = 11.5 million lbs/sq inch)
	d = wire diameter in inches
	N = number of active coils
	D = mean coil diameter in inches

The values for d,N and D for the various RX7 springs are in the workshop manual. The results verify my readings.

When measuring the spring rate, it is important to precompress the spring approx. to the length it has when fitted in the car. The reason for this is to make sure the number of ACTIVE coils is correct - otherwise the end coils take part in the springing. The force required to precompress the spring to that length usually is far beyond the range of a simple scale - that's why I bought the Intercomp (not Intergraph as I wrote) spring tester. So much for the coil spring rate - lets talk wheel spring rates now.

	W = C/S**2


	W = wheel spring rate in pounds/inch
	C = coil spring rate as determined by calculation above or 
	    direct measurement
	S = suspension leverage (wheel movement/coil movement)

S is the tricky part:

	S = AB/CB * cos(I)


	AB = distance between outer pivot point A and inner pivot 
	     point B of lower A-arm
	CB = distance between shock absorber pivot point C on lower 
	     A-arm and pivot B
	I = inclination of shock absorber in degrees from vertical

Again, there is a handy method to verify this:

This needs to be measured with as much accuracy as possible as this value will be squared in our calculation and obviously any error will also be squared. The ratio (suspension leverage) is found by measuring the exact amount of movement of the spring for a given amount of wheel movement. One practical method to obtain this is as follows. Block up the chassis at its normal ride height and, with the springs removed and the sway bar disconnected, measure the distance between the upper and lower spring location collars ( or use the positon of the damper shaft as a reference). Then without disturbing anything else, place a spacer of known thickness between the tyre and the ground and remeasure the distance between the spring collars (or check how far the damper shaft moved into the damper). The thickness of the spacer (wheel movement) divided by the difference between the two collar distances (or shaft movement) is the ration we are seeking.

You requested the sway bar diameter and arm length. Although this is needed to determine total roll stiffness ( spring roll stiffness AND sway bar roll stiffness) , it has NOTHING to do with wheel spring rate.


Date: Mon, 21 Dec 1998 12:19:24 +0100
From: "Bernd Kluesener"

                                R1 front        R1 rear        R2 front         R2 rear

Wire diameter                     0.49            0.48            0.48            0.48
Number of active coils            4.27            4.21            4.02            4.21
Mean coil diameter                4.13            4.516           4.12            4.516
Free length                      10.74           11.77           10.50           11.93

Spring rate lbs/in              269.5           192.5           265.5           192.5
Spring rate kp/mm                 5.01            3.58            4.94            3.58


Date: Mon, 27 Apr 1998 15:03:04 -0500
From: Steve Cirian

>I have the same sag on the driver side. I have about a 1" difference
>from the drivers side vs the passenger side. My suspension is all stock
>so far. I planning on changing to Eibachs with Tokico shocks. I hope
>this will even things out. From what I hear from others, it the shocks
>that are worn out.

Nope. The shocks do not have anything to do w/ ride height (unless you have aftermarket coil-overs w/ adjustable spring perches, but that's a whole different story). Sag is caused by springs. BTW, this doesn't affect the spring rate, just ride height, which has its own issues.

Shocks should not have anything to do w/ ride height, unless the shock is too stiff for the spring (i.e.- you bought a too stiff shock or used too light of springs). Or unless you are driving around in a '69 Chevy Nova w/ airshocks pumped up to about 90 PSI.

But I think you said you had stock springs/shocks, so the shocks are not the problem.

New springs should fix sag problems.



Eibach makes two different kinds of springs - progressive and linear. The progressive ones should give a bit better ride for the street. I believe the ProKits are progressive.

The linear ones are probably what you want to go with for autox / racing, I have the ERS race springs on my car, they are linear. 550 front, 300 rear. Way too stiff for the street, unless you want to wear a mouthpiece to keep the fillings from being rattled out of your teeth, or you only do a little street driving.

These come with helper springs, short, no spring-force to speak of, springs whose sole function is to keep the parts all lined up when you jack the car up and the suspension sags down once the load is off.

These are what came with my Penske coil-overs from Tri-Point.



Date: Wed, 15 Apr 98 07:10:36 -0500
From: "Linthicum, Sandy"

The Pro kit springs which are stiffer than stock and are what most people use who are going to use the car on the street are rated at:

5525.001                4.25 inch constant diameter , 9-9.25 free length
                        Fronts                   365 spec lbs/in

5525.002                4 1/8 top, 4.5 bottom diameter 
                        Rear                     275 spec lbs/in

It's next to impossible to accurately predict ride comfort when you are changing the ride height. You are probably just going to have to try them and see.

Eibach Pro's are linear. I measured mine on a spring tester prior to installation.


Date: Thu, 21 May 1998 16:47:22 -0700
From: Gene Kan

I'd pay the extra bucks and go with Eibach, a name I trust.

> of praise. I have got mixed answers on weather the Eibach (prokit
> springs) are linear or progressive or linear, anyone know for sure?

Prokits are normally progressive but I suppose they could be linear for the RX-7. Give Eibach a call, or I believe on that site they sing the praises of progressive springs and ride comfort, so I doubt there are linear Prokits.


Suspension Techniques

Date: Thu, 21 May 1998 16:47:22 -0700
From: Gene Kan

This is based on my experiences with a 1989 Acura Legend Coupe. And word of mouth among my little brother's high school friends in Southern California, home of the slammed import car.

Suspension Techniques is linear. They also suck in terms of quality control. My Acura's springs had completely different spring rates and the car sagged in funny ways after the springs settled. The springs in the rear were too stiff in any their app chart is not the best.

I'd pay the extra bucks and go with Eibach, a name I trust.



Date: Thu, 21 May 1998 16:53:32 -0500
From: "Dela Huerta, Damian"

Ok, I am going to go with new springs soon and did some research. (The advanced suspentioneers can save me some humility by ignoring this message...he he he)

This is what I found:

Pettit Racing (954 735 0100)
track-pro springs               $299.95

MazdaTrix (562-426-7960)
eibach springs          $277.17
suspension techniques   $203.97
rb (racing beat) springs        $208.00

Rotary Performance Online (972) 530-3335
suspension specialists  $239.95

PFS (703-368-7959)
comfort sport springs   ??
pro kit race springs    ??

In general, all the springs lower the car from the stock setup and provide a higher spring rate (except the pfs comfort springs, they are progressive and start out less stiff than stock and end up stiffer than stock as they are compressed). Most of these spring are for street and/or light to moderate racing/autoxing. I found that the hard core racers usually have custom coil over suspension systems (very expensive but very impressive). Racing Beat and Eibach springs seemed to get a lot of praise.


From: Steve Cirian
Date: December 15, 1999

>Can I just cut the stock springs down to reduce ride height?

Cutting them will change the spring rate (make them stiffer). Spring rate is a function of length (don't have the calculation handy, but do a search for "auto" and "calculator" or something similar for the web sites that have a ton of automotive cxalculations on them. There is probably a link from my site; do a search there.).

You will have to cut these with a saw of some sort, which if it is a hack saw will be a bear due to the hardness of the metal. Do not use a torch, as this will end up softening the metal and relieving tension.

One other thing to take into account is that I think the stock springs are flattened near the ends so they will rest flat against the spring perch. Cutting them will take the flat surface off, so they will tend to dig into the rubber mounts on the shocks. This could cause problems down the road if the rubber mounts get gouged out and the spring hits metal. It could even allow the springs to get off center and hit the shocks since the rubber dougnuts also function to center the stock springs.


I don't know much about the Bilsteins. Here is a rundown on what I know (some of this from the list plus I have been doing a lot of research on the Konis and Penskes).

The Tokico Illuminas are good basic shocks, and reasonably priced. Don't know if they are adjustable. Check Mazdatrix, Mazda Competition, and probably PFS and Pettit.

The GABs are more expensive, and adjustable. Supposed to be better than the Illuminas for performance. Available from the same places as listed above for the Tokicos.

The Konis are what most people use for autoxing the 3rd gens (some people use the GABs, but the majority seem to be on the Konis). I started out looking at these, and then having the double adjustable conversion done, and coil-over kit installed on them. The price got really expensive really quick, so I started looking at the Penskes, for not that much more than a full-on conversion of the Konis. There are two models of Konis, yellow and red. One is street (red) and the other is sport (yellow), but I am not 100% sure that I have the colors right. TrueChoice or Ground Control will do the conversion, and either sell you the shock or you can get them from Mazda Competition and save (not very much) bucks.

The Penske Shocks are the high-end choice, and what I opted to buy (should be here in a couple of days - oh joy!). Tri-Point will set them up for you exactly like they use on their ASP winning car, or you can get them "detuned" some if you want to do a lot of street driving (softer valving and springs). I am getting the double adjustables, but you can get singles and save about $75 a corner.

--Steve Feb 17, 1998


Date: Wed, 4 Nov 1998 10:45:42 -0800
From: "Jim LaBreck (ECA)" (

Looks like I have three choices for a full replacement kit...

1. Mazdaspeed - was $1,500, now up to $1,700, 4-way adjustable

2. Racing Beat - Type SR, $1,125 - adjustable?
                 Type SA, $1,325 - 16-way adjustable according to Shiv?

3. True Choice - Phase Two, $1,340, 5-way Koni, ride height adjustable
                 Phase Three, $1,990, Koni double-adjustable and ride height
                 Phase Four, $2,130+, Race-valved Konis with tender springs

And a couple choices for using my existing Koni 5-ways...

1. Ground Control - $499, ride height conversion kit... not the best, I'm told

2. True Choice - ~$800, Koni ride height conversion kit

So, who has what? Shiv gave a complementary review of the Racing Beat setup, and since it offers more adjustment for less money than the True Choice double adjustable setup, I'd be tempted to go for the RS*R Type SA kit. The Mazdaspeed kit was "affordable", but has now gone up $200 because of the damn Yen. :-)

Bear in mind (and this means YOU, Trev... :-) that the car will probably see very little track time. I have no time nor intent to compete in autocrossing or track events, and at most, the car might go to one of Todd Serota's events in California. The other uses will likely be a little bit of drag racing (3 import drag events in '99, which I will do my damndest to attend) and possibly, the Silver State Classic, although that might be wishful thinking. SO, with that in mind, don't necessarily apply what you use the car for to what I will be using it for. I'm more concerned with driveability (and therefore streetability) than I am with track use, although that is also a concern to a lesser extent.

In essence, I don't want just another means for lowering the car. I want a combination that rides well, is heavily adjustable for drag racing use, will perform well on the track, if necessary, and won't break the bank, since I'm just too damn sick of spending money on this car. The final total will probably drive me to drink. :-)


From: George Lynch (
Date: Thu, 27 Feb 1997 17:22:48 -0800 (PST)

>Okay, this is good, George can you help us out on this: You aparently have
>used the GAB Super R, and Koni (model???) on your car (???). Which ones do
>you like better and why? Which do you think are easier to get dialed in
>correctly, etc..????

PLEASE, I do not intend the following to be the last word on shocks, just what has happened to me.

I have run GAB Super, GAB Super-R, and KONI on the car. IMHO I get the best highway ride,(I drive to events in LosAngeles, SanDiego, Phoenix, LasVegas, and SanFrancisco) best feel of control, and best lap times (SOLO II) with the KONIs.

When I got the car I changed every thing at one time or another, not to make it better than what John gave me, but to understand how the car works. In Nov.'96 I put the car back to Johns setup and have been going faster. I now know what does not work!

I got the car with GAB Super-R on. John told me to run them at 7 front and 5 rear. I tryed other settings, but John was Right. Next I tryed the GAB Super (non-R). John told me to run these at 8 front and 6 rear. Testing other settings proved John was right again. Settings other than Johns made the car worst, never better. I got the same performance from both sets of shocks.

Adjusting the GAB changes compression and rebound at the same time. I started to wonder if this was a good or bad thing. I called Truechoice and ordered KONI Sport(8041-1169L&R fronts, 8041-1170 rear) $503.00. Truechoice did the SA to DA conversion for $680.00. The rebound (adjustable from KONI)is the same, but the compression can now be adjusted, and independent of rebound. The range of adjustment for compression is from softer than KONI factory to much harder than KONI factory. On my RX-7 the best setup for SOLO II is full soft compression front and rear, full hard rebound front and rear. My lap times are slower with any other settings. My lap times got faster after I changed from GAB to KONI.

To adjust the GAB, you have to reach over/around the tire to turn the adjusting knob. You will get dirty hands, arms(also burned from over heated tires), and knees. The KONI is good news/bad news. The KONI rebound is adjusted from under the hood and hatch. Clean and very easy. The bad news is that the compression is adjusted from the same location as the GAB. Also GAB has a knob on the shock for adjusting, KONI requires a screw driver(it hell to try to find that slot blind).

Dialing in the GAB Super-R is easy. I think everyone is runing the fronts at "7". Done deal! The rear are run between 2 and 5. Pick what works best for you. End of subject. The KONI may be a bit harder. Here is how I would do it. First, always look at your lap times more than how the car feels. I would start by installing my settings, then adjust the front rebound to get the best lap time and feel. Next do the rear rebound, then front compression and then rear compression. If I forget to set the rebound before my runs, my lap time will be around 1 1/2 seconds slower.


From: Ghsharp @
Date: 06/11/97 05:57 PM

> Koni or GAB??? Which models? Most of the people at the local autox
>use Konis, but that is with the stock R1 suspension. Is the Tokico
>Illumina almost as good as the others? (The price is a lot less.)

The Koni's have a much broader range of adjustibility than the Tokico's. This becomes more important when you start changing springs. If you are going to the expense of new springs, bars, and wheels, shocks are the wrong thing to scrimp on; they're the most important component in setting up a Solo II car, whether it's Stock or otherwise.

Try David Frye at 910-996-4080, he's a Koni WD and can answer any other questions you have.

Your best bet to answer your questions on springs and wheel sizes is Craig Nagler at Tri-Point Engineering (ASP National Champ last year). Don't have his phone # at my fingertips but they have ads in most of the car magazines. He's a straight shooter and has tried just about every combination of springs, shocks, tires, etc. already. Will probably save you a lot of grief and money.

G.H. Sharp
'95 RX-7 R2 SS#46


Date: Sun, 02 Apr 2000 01:23:43 -0500
From: Wael El-Dasher (

I agree with Steve, going to a tuner to buy specifically tuned shocks for your car is the only choice. I am sure you can buy them cheaper elsewhere, but you will not have them properly valved.

I believe M2 dropped Koni, my understanding is that Brian found it difficult to dial in consistantly because the adjustment has no values, rather measure by turns. He uses GAB-R's and is able to get consistant settings, don't quote me on this, I am going off my memory from an old discussion. But I am certain he makes a coilover kit using GAB-R's with custom springs built to purpose.


Date: Fri, 26 Jan 2001 20:33:09 -0800
From: "Max Cooper" (

Front GAB superR shocks: 6.0 lbs
Rear GAB superR shocks: 4.6 lbs

These weights are for new shocks as they come from the manufacturer (spring seats still in place), with no packaging or additional hardware (I did not include the nuts).


From: Albert.Chan @ ("Chan, Albert (GEP)")
Date: 06/12/97 07:10 AM

The top runners (G.H. Sharp, Tommy Pulliam, etc.) running on Koni use the yellow tube "Sport" model (8041-1169L & R for the fronts and 8041-1170 for the rears). This is the one that is more aggressively tuned for autocross/time trial usage. It has a snap-ring (three positions) by which you can change the ride height, and is rebound-only adjustable.

G.H., Pulliam, and others have had them converted to double adjustable by Truechoice in the Columbus, Ohio area. This way, you can adjust rebound and compression separately. From what I understand, that is the key to making these work for autocrossing. It's not a cheap conversion (I'm paying $300 each, including dyno testing.), but if you want the best, that's supposedly the set-up.

One tip. See if Truechoice can put your bump (shock body) adjustor towards the top of the assembly. I have mine at the bottom, and it's difficult to get to. To adjust the rears requires jacking the car partly up. Also, if you're "stuck" with having the bump adjustor at the bottom, make sure that the adjustors face forward. If they face rearward, they will be in close proximity to the rear bar, and you may not be able to get to it (depending on your ride height).

Hope that this helps, and good luck!
Al Chan


From: Albert.Chan @ ("Chan, Albert (GEP)")
Date: 06/12/97 12:28 PM

> Is it $300 for the shock and conversion, or just for the conversion
>(i.e.- you provide the shock, and they do the conversion for $300)?

The price is $300 just for the conversion. Add onto that the cost of the shock themselves; I bought them from Mazda Competition at about $130 each. So, for your budget, if this is what you want, count on $1750 or so.

With you running in street prepared, you may want to see if Truechoice can cut threaded adjusters in the shocks; that would give you true corner weight balancing/tuning ability.

As a comparison, you can pick up the GABs from Pettit (who I got mine from last year) for about $750, if my memory is correct.


Tri-Point sells the Penske shock, as used on their ASP champion car. These are not cheap, but is you are going coil-over, they are not much more than the Konis once all of the conversion work is done on the Konis. Plus Tri-Point knows what valving to use, spring rates, etc.


Date: Fri, 24 Oct 1997 12:11:29 -0800
From: Dennis S Pedersen

>Can anyone tell me how you tell whether your shocks are bad or not??

It should be fairly easy in theory. Just press down on one corner of the car at a time (don't press on the fenders as that will dent them... press on the top of the struts by opening the hood and hatch to gain access), hard enough to cause the springs to compress about an inch or more. Then see how quickly the rebound motion stops. If it bounces back up, then moves down before stopping, it's worn. If it bounces back up and _just barely_ starts to move down it's good.

However, the 3rd gens have very stiff strut valving, and it may be difficult to compress them enough. In that case you may want to pull them out of the car and test them (see The Shock Tester Company for some interesting info on shock testing). It's a bit of a hassle though. You might also be able to tell by test-driving the car and checking whether the car tends to bottom out a lot and bounce through more than one up/down cycle after hitting a given bump, especially on speed bumps.


From: Spathak [] Sent: Sunday, February 13, 2000 9:35 AM

FWIW, I recently compared the shock dyno results of the following shows: '93 Touring, '93 R1 Bilsteins, GAB Super R, and Koni single adjustables. The biggest difference between the Touring/base and R1 shocks is that the R1s have an boat load of front rebound dammping. All things equal, this should reduce squat under acceleration, improve turn-in, and "tighten up" the front of the car without actually changing the car's overall cornering balance as it would with stiffer front springs.

                Stock Front                     Stock Rear                                                                                                                                                                                                                                                                              
Velocity                Compression     Rebound         Compression     Rebound                                                                                                                                                                                                                                                                 
0               0       0               0       0                                                                                                                                                                                                                                                                       
0.25            25      25              25      30                                                                                                                                                                                                                                                                      
0.5             30      30              30      35                                                                                                                                                                                                                                                                      
1               50      60              50      75                                                                                                                                                                                                                                                                      
2               80      120             80      170                                                                                                                                                                                                                                                                     
3               100     200             100     250                                                                                                                                                                                                                                                                     
4               110     280             105     275                                                                                                                                                                                                                                                                     
5               125     375             110     310                                                                                                                                                                                                                                                                     
6               130     405             115     320                                                                                                                                                                                                                                                                     
7               150     430             135     340                                                                                                                                                                                                                                                                     
8               160     460             145     360                                                                                                                                                                                                                                                                     
9               170     475             155     375                                                                                                                                                                                                                                                                     
10              175     500             160     400                                                                                                                                                                                                                                                                     
                R1 Front                        R1 Rear                                                                                                                                                                                                                                                                         
Velocity                Compression     Rebound         Compression     Rebound                                                                                                                                                                                                                                                                 
0               0       0               0       0                                                                                                                                                                                                                                                                       
0.25            -20     100             -15     30                                                                                                                                                                                                                                                                      
0.5             -30     200             -25     50                                                                                                                                                                                                                                                                      
1               -50     300             -40     90                                                                                                                                                                                                                                                                      
2               -80     450             -50     175                                                                                                                                                                                                                                                                     
3               -90                     -65     260                                                                                                                                                                                                                                                                     
4               -95                     -80     340                                                                                                                                                                                                                                                                     
5               -100                    -85     425                                                                                                                                                                                                                                                                     
6               -105                    -90     460                                                                                                                                                                                                                                                                     
7               -105                    -90     480                                                                                                                                                                                                                                                                     
8               -105                    -90     500                                                                                                                                                                                                                                                                     
9               -110                    -95     500                                                                                                                                                                                                                                                                     
10              -110                    -95     500                                                                                                                                                                                                                                                                     
                Koni Front                                                      Koni Front                                                                                                                                                                                                                                              
Velocity                Compression 1   Compression 2   Compression 3   Compression 4   Compression 5   Compression 6           Rebound 1       Rebound 2       Rebound 3       
Rebound 4       Rebound 5       Rebound 6                                                                                                                                                                                                       
0               0       0       0       0       0       0               0       0       0       0       0       0                                                                                                                                                                                                       
0.25            -5      -5      -5      -5      -5      -90             10      10      10      10      10      100                                                                                                                                                                                                     
0.5             -15     -15     -15     -15     -15     -95             20      22      24      26      28      200                                                                                                                                                                                                     
1               -20     -20     -20     -20     -20     -97             90      100     120     125     130     260                                                                                                                                                                                                     
2               -35     -35     -35     -35     -35     -105            200     210     225     230     250     340                                                                                                                                                                                                     
3               -45     -45     -45     -45     -45     -115            240     270     300     305     325     400                                                                                                                                                                                                     
4               -75     -75     -75     -75     -75     -150            260     315     370     375     375     440                                                                                                                                                                                                     
5               -100    -100    -100    -100    -100    -170            280     350     430     440     460     470                                                                                                                                                                                                     
6               -120    -120    -120    -120    -120    -195            290     380     460     465     480     500                                                                                                                                                                                                     
7               -140    -140    -140    -140    -140    -215            310     410     490                                                                                                                                                                                                                             
8               -160    -160    -160    -160    -160    -225            330     430                                                                                                                                                                                                                                     
9               -165    -165    -165    -165    -165    -225            350     460                                                                                                                                                                                                                                     
10              -170    -170    -170    -170    -170    -230            370     480                                                                                                                                                                                                                                     
                Koni Rear                                                       Koni Rear                                                                                                                                                                                                                                               
Velocity                Compression 1   Compression 2   Compression 3   Compression 4   Compression 5                   Rebound 1       Rebound 2       Rebound 3       Rebound 4       
Rebound 5                                                                                                                                                                                                               
0               0       0       0       0       0                       0       0       0       0       0                                                                                                                                                                                                               
0.25            -20     -20     -20     -20     -60                     15      15      15      15      100                                                                                                                                                                                                             
0.5             -25     -25     -25     -25     -65                     20      30      35      50      125                                                                                                                                                                                                             
1               -30     -30     -30     -30     -70                     50      75      80      115     175                                                                                                                                                                                                             
2               -40     -40     -40     -40     -90                     120     17      175     200     250                                                                                                                                                                                                             
3               -50     -50     -50     -50     -100                    160     210     240     270     315                                                                                                                                                                                                             
4               -80     -80     -80     -80     -130                    195     250     300     340     380                                                                                                                                                                                                             
5               -105    -105    -105    -105    -160                    220     300     355     400     440                                                                                                                                                                                                             
6               -120    -120    -120    -120    -175                    250     340     415     455     500                                                                                                                                                                                                             
7               -140    -140    -140    -140    -195                    280     380     475                                                                                                                                                                                                                             
8               -150    -150    -150    -150    -200                    310     420                                                                                                                                                                                                                                     
9               -155    -155    -155    -155    -205                    330     460                                                                                                                                                                                                                                     
10              -155    -155    -155    -155    -205                    350     500                                                                                                                                                                                                                                     
                GAB Super R Front                                                                       GAB Super R Front                                                                                                                                                                                                                               
Velocity                Compression 1   Compression 2   Compression 3   Compression 4   Compression 5   Compression 6   Compression 7   Compression 8           
Rebound 1       Rebound 2       Rebound 3       Rebound 4       Rebound 5       Rebound 6       Rebound 7       Rebound 8                                                                                                                                                                       
0               0       0       0       0       0       0       0       0               0       0       0       0       0       0       0       0                                                                                                                                                                       
0.25            -10     -12     -14     -16     -18     -20     -22     -24             11      15      20      27      35      38      40      55                                                                                                                                                                      
0.5             -33     -35     -37     -39     -41     -43     -45     -60             22      30      40      55      70      75      80      110                                                                                                                                                                     
1               -60     -62     -64     -66     -68     -70     -72     -100            45      60      80      110     140     150     160     220                                                                                                                                                                     
2               -100    -105    -110    -115    -120    -125    -130    -160            120     140     200     250     275     285     310     380                                                                                                                                                                     
3               -125    -130    -135    -140    -145    -150    -160    -215            200     250     310     355     380     400     430     480                                                                                                                                                                     
4               -150    -155    -165    -175    -185    -195    -200    -260            300     350     410     450     480     500                                                                                                                                                                                     
5               -180    -190    -200    -210    -220    -230    -240    -300            380     445     500                                                                                                                                                                                                             
6               -205    -215    -235    -245    -260    -270    -280    -350            475                                                                                                                                                                                                                             
7               -230    -240    -250    -270    -285    -300    -315    -390                                                                                                                                                                                                                                            
                GAB Super R Rear                                                                        GAB Super R Rear                                                                                                                                                                                                                                
Velocity                Compression 1   Compression 2   Compression 3   Compression 4   Compression 5   Compression 6   Compression 7   Compression 8           
Rebound 1       Rebound 2       Rebound 3       Rebound 4       Rebound 5       Rebound 6       Rebound 7       Rebound 8                                                                                                                                                                       
0               0       0       0       0       0       0       0       0               0       0       0       0       0       0       0       0                                                                                                                                                                       
0.25            -20     -21     -21     -22     -22     -23     -24     -25             12      18      20      27      38      40      50      62                                                                                                                                                                      
0.5             -40     -42     -43     -44     -45     -46     -48     -49             25      35      40      55      75      80      100     3                                                                                                                                                                       
1               -50     -52     -54     -56     -58     -60     -65     -85             50      70      80      110     150     175     200     250                                                                                                                                                                     
2               -80     -82     -84     -86     -88     -90     -95     -145            130     165     205     275     315     335     345     355                                                                                                                                                                     
3               -95     -96     -100    -105    -110    -120    -130    -185            240     275     320     380     405     410     415     425                                                                                                                                                                     
4               -105    -110    -115    -120    -130    -140    -155    -240            355     385     410     450     475     480     500                                                                                                                                                                             
5               -120    -125    -130    -135    -145    -175    -200    -275            440     460     480                                                                                                                                                                                                             
6               -140    -145    -150    -160    -175    -205    -225    -315            480                                                                                                                                                                                                                             
7               -160    -165    -170    -185    -210    -240    -260    -350                                                                                                                                                                                                                                            


Mark Valskis ( input the above data into Excel and created graphs. He also added data he obtained directly from Bilstein. April 5, 2000.

Chart of Stock (Touring, PEG, Base) Data

Chart of R1 Data

Chart of Koni Front Data

Chart of Koni Rear Data

Chart of GAB Front Data

Chart of GAB Rear Data

Chart of Bilstein Data


Date: Tue, 15 Feb 2000 12:11:38 -0500
From: Spathak (

> Shiv, just a couple questions after a cursory view of the data ( I'll save
> the rest for the article): 1) What's with the magical 500...would these be
> the measurement limits of the shock dyno? 2)The data suggests you had the
> Koni's upgraded to double-adjustable, in which case there exist a multitude
> of valving profiles...can you provide more details on the profile choice
> and who made that determination; 3) do you anticipate tests of the Tokico
> Illumina and Bilstein units? The former are a very popular upgrade and the
> latter are OEM on the '96 and later RZ and Miata R's (plus we get to
> compare the response of a monotube design to the twintube designs).

500lbs was the typical upper limit for measurment. I think the dyno can read higher, if needed. But I don't think it's needed for these comparison purposes.

We tested Koni single ajdustables, not double adjustables. Notice that compression does not change appreciably until adjusted full 100% stiff. Then, all of a sudden, compression and rebound become rock hard. The Konis were tested at full soft, full stiff, and 1, .5, and .25 turns back from full stiff.

I couldn't locate any Tokicos for the test but the Bilstein/R1 results are included.


Installed Rear Shock

You really want to buy coil-overs from a shop that will build them specifically for your car. A lot of the places will simply take an off-the-shelf shock and add a coil-spring to match the shocks valving. Or worse yet, not match it.

This should really be done as follows:

  1. Determine usage (road course, autox, street, drag)
  2. Determine total weight of car and corner weights
  3. Pick a spring rate
  4. Determine shock valving based on all of the above

Shops that have RX-7 expertise should already know these numbers and be capable of building you a shock that will work properly. I would suggest Tri-Point or Mostly Mazda.

>If I am going to put the 17 x 10" wheels and tires on my car, a
>lot of people have recommended going to coil-over shocks. This should
>give a little extra clearance.

True. Some coil-overs use 2.25" springs, while most aftermarket, like Eibach, are 2.50", but some Eibach springs are also 2.25". Not sure what the diameter of the stock springs are. If you buy springs for the stock shocks and go to aftermarket shocks, you may be able to re-use the springs, but make sure they are compatible spring diameter-wise.

>What brand/model of coil-over shocks are people running?

The ones I have found are:

>What diameter are your coil-overs? I know you can get the Eibach
>springs in 2.25" diameter. How much will the coil-overs save?

None over the smaller Eibachs, see above.

>Are the coil-over shocks adjustable in the same manner as regular
>adjustable shocks?

Yes. You also get adjustability on spring height as well. The spring perches are adjustable up and down to adjust ride height and do corner balancing.

>What is the difference in spring rates? I know you can get the
>Eibach springs in almost any rate.

You can get any spring rate you want, but make sure the shocks can handle the springs, and vice versa. It is best to buy these as a set from a tuner who knows the type of car you have. For 3rd gen RX-7s, I would recommend Tri-Point, Pettit, or PFS.

>Any pros/cons to using coil-overs in autocrossing?

Puts you into the Street Prepared classes. There they are pretty much mandatory. Pros are ride height lowering for lower center of gravity, allows you to do corner balancing, and smaller spring diameter gives more room for big tires/wheels.

>How are coil-overs different from the stock setup? It sounds like
>the stock setup is more or less the same?

In general layout, that is true - the spring surrounds the shock. In the stock setup on the 3rd gen RX-7, the spring is mounted to the shock and that's it. This is the "text book" definition of coil-over. However, most people seem to agree that "true" coil-overs also need to have adjustable spring perches. See below for pictures of my Penske coil-overs and the stock shocks/springs.

This adjustability, plus the changed spring rates and sizes, is what will put you into the street prepared class.

Steve Cirian
'95 RX-7 TT: Lightning in a world of thunder
#494 SCCA Chicago Region
TSSCC (Tri-State Sports Car Club)


I got the following from Tri-Point (they are a vendor, so the usual comments apply. However; their car won the Solo II Nationals in ASP last year, and was in the running again this year, so they do know what they are doing.). --Steve

Date: Mon, 29 Sep 1997 21:42:26 -0400 (EDT)

Steve, your best bet is to buy Penske shocks. At TRI-POINT ENGINEERING we already know the valving you need. We've tested many shocks and different valving set-ups. The Penske shock is better for your needs, piston sizing is much bigger for a start, on the Penske shock. The Penske shocks' pistons are bigger than the street Koni. The bigger piston, displaces more oil-making it more sensitive. We have the shock valving and the spring rates that work! The price for the correct shocks and springs are only slightly more than the Koni's. Penske shocks front are $625.00 ea. and the rears are 675.00 ea. These are Penske Winston cup single adjustable aluminum shocks w-coilover kit, same valving as our race car.We use and sell Eibach ,also and will supply you with the same spring as our race car.By the way you've been mis-informed as to the spring rates we use in our car. Please call for further info at 818-348-5385 and ask for me-----GUY ANKENY. THANKS

I sent you info regarding Penske single adjustable, (rebound) shocks. I recommend these because they are much better than double adjustable Koni shocks (for your application). Once compression valving is determined for unsprung weight, there's really no reason to change it. SIDE NOTE: In stock classes, double adjustable shocks are really a big help, because you're trying to make them do things shocks aren't made to do (because of the rules). We've tested alot with valving and spring rates, once a combination is found to work, it works everywhere. Craig very rarely will make shock adjustments to his car, and I've never seen him change compression damping. ---The price for double adjustable Penske's are 700.00 ea fronts and rears are 750.00 ea. The price on Eibach springs are 60.00 ea. Thanks - GUY


I bought the Penskes from Tri-Point. Get ready for this, better sit down. They were $4040.

This breaks down as:

	PART			PRICE (ea)	PRICE (ext)
	double adj. shocks	$ 700		$2800
	collars			   50		  200
	bumpers			   12		   48
	mods to shocks		   75		  300
	springs (Eibach)	   70		  280
	helper springs		   65		  260
	spacers			   38		  152
	TOTAL			$1010		$4040

Ouch!!! --Steve

Note: The prices have gone up a bit. Contact Tri-Point for the latest. --Steve

The new Penskes are shown below, along with the stock shocks for comparison. The picture on the left is the fronts, and the one on the right is the rears. The picture at the beginning of the Coil-over section shows the rear unit installed.

Front Shock Comparison Rear Shock Comparison


One of the reasons you will pay so much for the Tri-Point coil-overs is that they will pick a spring rate, and then match the shock valving to the springs. Some of the other places I talked to will not do this. They will use stock Konis, and then match the springs to the standard shock valving. WRONG!

Now I feel better about paying so much (not that I was regretting it). --Steve


From: grigory @ (Steve Grigory) Date: 06/11/97 11:55 AM

I spent a few hours with Brian at Mostly Mazda in Concorde, CA and one of the cars in his shop was a yellow R1 that had coil overs and Brembos newly installed (along with 17" Forgelines) and I asked Brian why you would put coil overs on an RX7 since it pretty much has the same setup already on it (without the adjustability though) and his reply was that the only legitimate reason to add them was if you wanted to move up to a much stiffer spring rate compared to the aftermarket rates currently available for the RX7's. Granted, both of us are talking race track environment and not autocross but it's something to think about. Plus (and I hope he's right) the cost of the coil over kit is only about $600 (set of 4). Another nice benefit is that you can set the ride height to what you want and balance the weight at all four corners also if you can find the equipment to weigh each corner of the car. I have a racing buddy that has this setup and I think he will let me use it to tune the suspension.

My plan is to go with the coil over kit. It's pretty cheap and it's a great way to learn how to adjust and tune your car's suspension.

From the open track events I've run it's pretty obvious that a few thousand dollars spent on your suspension (even one as good as 3rd Gen RX7's) will get you around the track faster than the same amount spent on hp mods.

My advice would be to check into coil overs before you decide which springs to buy.


Date: Tue, 22 Jun 1999 14:02:46 -0500
From: Wael El-Dasher (

Before you jump in head first into the Ground Control setup you might want to consider the coilover setup Brian sells at Mostly Mazda. He uses GAB R's.

There is an advantage to buying from an Rx-7 tuner, they can test and dial in the setup before they ship it to you. Brian can also spec whatever spring rates you choose.

He also ran both Koni and GAB R in the two world challenge cars so he can give you a good comparision between both setups. You might have already took all that into consideration, if so I appologise, if not then give Brian a call (925)686-9047, see what input you might gain from his experience.


The following are my notes after doing a little more research --Steve:

> I got the following info from TrueChoice:
> 1.  The price for the shock is $145 each for the Koni Sport model:
>       8041-1169 (front) (specify L or R)
>       8041-1170 (rear)
> 2.  The double adjustable conversion is $250 each.  The adjustment is
> done at the top with a plastic wheel that detaches, and at the bottom
> through a screw in the side of the shock (adjustable on the car).
> 3.  The coil-over conversion is $225 each.
> 4.  Revalving to match the spring rates (if changed from stock rates)
> is $100 each.
> 5.  If you buy the shock from them and have them do all the above work
> at once, the price is quite a bit lower at $520 each including the
> shock
> itself, since they will already have it apart and all of the work is
> much easier if done at the same time.
> 6.  The Eibach springs are $60 each.
> Now on to some questions:
> 1.  What model of Eibach?  (I want 2.25" for added tire clearance.)
> 2.  What spring rates are people using?  Tri-Point is using 450 front
> and 275 rear on their car.  Since the car is 50/50 balanced front to
> rear, why would they be different?  To increase resistance to dive
> under
> braking?  Due to different geometry front/rear?  What are the stock
> rates?  Are they the same front/rear?

A different person from Tri-Point said these are not the correct spring 
rates they are using.

> 3.  Anybody priced the basic shock through Mazda Competition Parts to
> see what they get for the shocks only?  

I did get an answer on this - Mazda Comp charges about $139.XX for them, 
so you will not really save any money.  Just buy the whole thing through
TrueChoice, and saving the cost of shipping will probably about equal it out
plus less hassle.

> 4.  What differences in mounting will coil-overs involve?  I would
> assume coil-overs should use the stock mounting points since the basic
> shock is a stock replacement.  What difference does the coil-over
> spring arrangement make?


From: Grant Moyer
Date: April 13, 1999

It finally sunk in that the package I'm looking at is a STANDARD Koni shock modified to be a coilover and the spring rate is determined to match the shock's valving. I am not picking a spring rate and then they valve the shock to match. I imagine there is some leadway or range of rates that will work at the valving. At least I'm pretty sure about all that... :-)

I also asked some questions of Kyle Krutilek because he was the one who really got me thinking of coilovers instead of just the basic shock/spring combo. He had some problems dealing with Truechoice and ended up using NTech to get a Ground Control kit. I kind of want to use NTech because Nick is involved with the list and seems helpful. I just have a better image of Truechoice's quality. That may not be accurate... We'll see.

Editor's note: when I talked to TrueChoice, they were going to re-valve the shock. I guess it depends which package you are looking at. Make sure that they will/will not revalve according to your desires/budget. --Steve


From: Steve Cirian (
Date: April 24, 1998

Coil-overs will allow you to do corner balancing. Corner balancing is were you stick racing scales under each wheel. You then add diagonal weights together (i.e.- Left Front (LF) + RR, and RF + LR. These weights should be equal. If not, raise the spring on the heavy corner to lighten it, or lower the light corner to increase weight. That is why you want to go to adjustable springs. (Besides just lowering the car will improve handling by lowering the center of gravity.)

Some companies have coil-over kits which fasten to the shock body. These are threaded sleeves that accept spring perches. The perches screw on the sleeve and the spring sits on them, supporting the spring at the bottom. Other manufacturers cut threads in the shock body itself, e.g.- the Penskes I am using.

You need special scales, since a bathroom scale will not go high enough. The scales run about $1200 or more, so usually you want to find a racing shop that has the scales. There is a company called RuggleScales which uses bathroom scales and a lever system to reduce weight to what the scales can register. They advertise in the SCCA's mag "SportsCar".


Ed.'s note: My coilover springs on my [3] may be different from what you are describing. Mine are stacked, one on top of the other. The main springs are something like 550/350 lbs F/R (linear), and the helper springs are negligible in rate.

The helper springs are not intended to add any rate at all when the car is down off of the jack stands. They are intended to keep all of the other components located while the car is up in the air. The main springs pull out of the upper locating perches when the car is up in the air, and might not line themselves back up into the perches when the car is dropped back down onto the tires. The helpers compress fully (absolutely flat) when the car is dropped.

You could compress them with your thumb and little finger - that is how soft they are. They are definately not supposed to give any sort of non-linear type rate.


Date: Mon, 6 Jul 1998 18:51:41 +0200
From: "Bernd Kluesener" (

Mazdaspeed Ride Height Adjustable Suspension Kit for 3rd gen (FD3S)
Part number: 9CD6 30 001
List price: Yen 198.000

CSI 714 879-7955
Contact: Ben Miller

Date: Sun, 21 Jun 1998 22:45:17 +0200
From: "Bernd Kluesener"

I have used this kit for about 4 weeks now.

I have no experience with the Penskes. I compared them back to back with my swedish made Ohlin shocks (similar to the Penskes, remote reservoirs, countless adjustments, totally rebuildable etc.) on a road type race circuit. The Mazdaspeed damper/spring units are definitely worth their money. I would guess that they give You 90% of the performance of Penske/Ohlin/Spax/JRZ etc. for 25% of the cost.

Especially for fast road use I would prefer them over both the Konis and Tokicos (which I didn't like at all) because of the slow shaft velocity rebound setting which gave me very much FEEL for the car (the Tokico's didn't give me any feedback whatsoever).

Apart from that, Mazdaspeed sells You a complete solution: adjustable shock, progressive springs, coil overs, upgraded upper shock mounts (the OEM ones are so bad You need to replace them anyway) - and everything is preassembled.

Technical data Mazdaspeed kit:

Spring rate front primary 282 lbs/inch
Spring rate front secondary 412
Spring rate rear primary 229
Spring rate rear secondary 288
Front bump damping force at 12 in/s shaft velocity: 
    4 settings from 229 to 267 lbs
Front rebound at 12 in/s : 4 settings from 667 to 778 lbs
Rear bump 4 settings from 178 to 222 lbs
Rear rebound 4 settings from 600 to 778 lbs
Ride height change compared with stock: +1/2in to -1in
Means of adjustment: turning knob on damper unit, accessible without
removing wheel

BTW, I measured the spring rates myself. The stated damping forces are from the Mazdaspeed manual.

> Anyone know of a different source than for these things?

I bought mine from CSI Inc. in LA ((714-879-7955). Nice people. They read and speak Japanese. Could come in handy one day.


Date: Mon, 06 Jul 98 12:14:56 -0500
From: "Linthicum, Sandy"

Mostly Mazda has a beautiful coil over kit for GAB's Tokino, or Koni's for about $600. After lots of research, this is what I put on my car.

I am sure Mazdaspeed's kit it also nice but I do not think there is any way it is any better that MM's and it is nearly 3 times the price if I remember correctly. The only way this would a reasonable value is if the Mazdaspeed product includes race ajustable shocks as part of their price (about $1500).


Date: Mon, 6 Jul 1998 14:13:18 -0700 (PDT)
From: Skye Comstock

You get 5 way shocks, springs, and the threaded coil overs, plus an improved shock mount... I'd say that was pretty good for a full FD set-up, considering how expensive most other set-ups are for this car. I've heard a lot of good stuff about the package, and since everything was designed in tandem, it might even work better than a mish mash of (albeit good) parts.


Date: Thu, 02 Mar 2000 14:30:50 -0800
From: "Shiv Pathak" (

> Has anyone ever contacted LEDA suspension,, about creating (if
> they already don't have it) a coilover setup for the 3rd gen?  I had them do
> a set for the Probe/MX6/626 triplets and they're simply awesome.  SCC is
> using them on the Imprezza 2.5RS as well.  REALLY quality stuff.  Double
> adjustable (seperate adjustment for compression and rebound) true threaded
> shock body, completely rebuildable, custom spring rates matched to your shock
> valving (well vice versa really), and of course ride height adjustable.  They
> come in three packages, non-adjustable, adjustable oil dampened, and
> adjustable gas dampened.  I think the gas has a remote resovoir.  Cost
> started at under $1K and went up to $2K I believe.

The gas charged Ledas have been removed from the Impreza. They leaked oil and had less than streetable low speed damping characteristics. How does 80lbs of stiction sound? Ugh. Felt great over bumpy surfaces but way too undamped on relatively smooth roads. It's a real rally shock. Doesn't seem to be ideal for the street.

> Now I don't really have the time to do all the research or send them a f/r
> shock, but if someone on the list does have a bit of time, give them a call
> here in the States and talk to Danny.  That's who I dealt with.  They're also
> into group buys.  The person who takes the time to send them shocks generally
> gets a discount, FYI.  I'm currently downloading their catalog (PDF format)
> and will report back if they already have an app for the 7(3).
> I may (and probably am) wrong, but I always saw the GC coil overs with
> aftermarket shocks as somewhat of a compromise.  I think the LEDA uses a
> 2.25" OD spring and they're pretty damn light.  Less unsprung weight in a
> matched package all from one company.  Now when Shiv and SCC swapped out the
> RSR setup for the M2 stuff, I was a bit suprised.  I'm a suspension newbie,
> but it seems that the tail happy attitude could have been adjusted with
> different spring rates...or was it the shock valving/damping rates?

It was the valving. The pillow ball mounts also clacked a bit.


Note: the following may only apply to Tokicos converted to coil-overs, but this is a good question to ask of any company converting regular shocks to coil-overs. Good conversions will have shock bodies that are threaded instead of something like the setup described in the following note. --Steve

Date: Wed, 05 Apr 2000 08:21:03 -0400
From: Jason Burger (
Subject: (rx7) Re: (FC3S) Question about GC coil overs????

> i just got my Ground Control coil overs and i have a few questions. first,
> whats with the rubber o-rings to hold the threaded sleve in place? any one
> else find this a little cheesy?? second how do you get the orings to stay in
> place as you slide the sleeve over it.  and why do you have to grind the top
> ring, on the front struts, down to 2" if you have tokicos?

Yes, the O rings are cheesy. The larger one sits at the bottom of the threaded sleeve where it meets the perch. It doesn't have to be inside. The smaller one I just used a screw driver to slip in from the top after I put the sleeve on so it didn't roll to the bottom while trying to slide it on.

If you have the old Tokico Shocks, the shock core cap was bigger than the newer ones and it may be required to shave it down a little to get the sleeve over them. I didn't have to mess with it since I have the newer style with the smaller caps.

What size spirng did they send you? They messed mine up and my car sits at stock level in the front with the adjuster as low as it will go. It's taken them two weeks to send me the right size coil for the fronts and that is assuming I will see them tomorrow like they say. The back sits perfectly where I want it.

They sent me 7" coils for the front and 8" coils for the rear.


From: Mark Valskis
Date: April 11, 2000

I just wanted to further clarify a few points on the shock damping data. The myth that the R1 shocks are Bilstein's has been strewn about quite a bit. This is untrue. The R1 shocks were produced by Showa (a Japanese suspension manufacturer) and are of a twin tube design.

All Bilstein shocks are of the high-pressure gas mono-tube design. The only Bilstein shocks which have been fitted to an RX-7 as standard equipment are those which were offered on the RZ models in Japan. The Bilstein shocks which are available for the RX-7 here in the states are indeed mono-tube shocks and look entirely different than the R1 shocks. They are much larger in diameter (which would mean more piston area to begin with, and then considering that they are mono-tube as well means huge increases in piston area), as well as having larger diameter shafts.

They are also bright yellow. I have included a picture of the ones which I use (with a Ground Control coil-over kit installed). The Bilstein damping curves that I provided you in the Excel spreadsheet (and which are not currently on your site) are for these shocks.

Bilstein Coilovers


Date: Thu, 20 Mar 2003 09:41:25 EST
Subject: (rx7) Subject: (3) Tein HA's coilover set

...Tein coil-overs... my advice is to grab them. i have run the RS*R coil-overs (they were re-badged Tein HAs) on my car since they were put on the Patek rx7 project car a number of years ago.

Racing Beat dropped offering them and Patek came up with some lame reason for switching them to another brand... something about too stiff in the rear and a ride height problem.

my track experience and tire temps tell me that the rear rate is right on the money. i run 25 inches (ride height) at the top of the wheel wells both front and rear and there is easily another inch if i wanted it. so much for ride height as an issue.

i have both a shock dyno and an expensive accurate spring rate checker. stock spring rate on an rx7 is 263 front and 195 rear... ( i have tested over 10 sets to come up with this number.). the eibach pro-track rate is 350 front and 255 rear. i recommend these springs.. use the stock shocks, spend $250 and you have a great all around suspension. they lower the car to very close to 25 inches which i consider optimum. i believe they are advertised as being progressive (which i don't like) but they are linear.

the RS*R coil-overs (Tein HA) are 432 front and 378 rear. i really like the rate for street and track and they do not have too much rate in the rear. my car generates the right amount of rear tire temperature at the track.

the spring rate relative to wheel rates for the rx7 is: one inch of front wheel travel is .6 of shock travel and the rear is .68. solving for actual wheel rate: front: stock is 96 pounds, eibach protrack 127 pounds, rs*r/Tein HA is 158 pounds and the ubiquitous 550 pound front spring is 200 pounds rated at the wheel. rear wheel rates are: stock 60 pounds, eibach 79 pounds, rs*r/Tein HA 117 pounds and the often used 450 pound rear spring is 208.

as an aside, interestingly if you put a 500 pound spring in the front and rear you would have a 182 pound wheel rate in the front and a 231 pound wheel rate in the rear and your car would hugely oversteer just because of the motion ratios being so different. there is a 50 pound wheel rate difference between the front and rear at around a 500 pound spring rate! virtually all front engine rear drive cars need less rate in the rear for road racing to hook up the driving force. if you take the wheel rate and the corner weight you can solve for a ratio that will enable you to get a handle on just what kind of performance dynamics to expect.

the stock rx7 carries 7.38 pounds of corner weight for each pound of wheel rate. the new mini carries 6.4 pounds so is a bit more stiffly sprung to offset a crummy (struts) suspension design. the eibach rx7 is a 5.6. i really like that relationship for street driving.

my rs*r/Tein HA is at 4.13 of wheel rate per pound of vehicle weight. one final point re the rs*r/Tein HA coil-overs. they are beautifully built and i like the shock adjustments. Tein makes great stuff and also has a few more expensive models but if you look at the spring rates on them someone must be smoking something as they are in the stratosphere. the same goes for the range of shock adjustments... they quickly become way too stiff but you just run them in the soft area of adjustment which works very well. for the money, my money is on the Tein HA package or Eibach Pro Track springs.


Date: Tue, 6 Jun 2000 01:07:40 -0700
From: "Jim LaBreck" (

Anyone interested in drag launch bushings? We recently manufactured our first two sets of bushings from white Nylatron (less brittle with superior wear/fatigue qualities when compared to Delrin) with pressed-in milled stainless steel center bushings... want a peek?

Want a closer look? The stock bushings are liquid filled and the center can be easily moved by hand, even on these *very* low mile bushings straight out of my car...

After talking to Mostly Mazda about getting a set of bushings, I was told they charged $79.95 a bushing (not $76/pair like the web site said...) and that the bushings were Mazdaspeed *rubber* bushings. I asked why I'd want to replace my near-new rubber bushings with other rubber bushings, and they said that they elected to provide rubber bushings (at substantial cost) to their customers because the Delrin bushings transmitted too much road noise to the passenger area...

Heh heh... too much road noise in a rotary-powered car. (well, not mine personally, but other people's cars... :) We laughed all the way to the drawing board, and this is what we came up with.

They also said that Mazdaspeed claimed that their rubber bushings were 50-60% stiffer than stock. Are you willing to bet $160 + shipping and 4+ hours of your time installing the bushings that they'll be "50-60% stiffer than stock"? Wouldn't you rather have a bushing that is absolutely, positively 100+% stiffer than stock?

After checking out Pettit's drag launch kit, priced at $599, it was obvious that an alternative was needed. These bushings are just the first of what may (and probably will) become a comprehensive replacement kit for all of the suspension bushings on the car. Want to replace just a few? No problem. We won't make you buy every last one (and rob a bank to do it) like some vendors... :)

So now, you ask, what are these ultra-fine differential mount bushings going to cost me? We're offering them for $90/set. They come standard in white, but you can have black for $100/set. (Sorry, the colored material is more expensive. Blue might also be an option, but we have not confirmed that we can get it yet.)

These are absolutely the finest, precision-milled bushings you'll find anywhere, and preliminary testing in a car (with approximately 60k miles) which previously had a nasty case of wheel hop (on P275 Kumho Victor Racers) completely eliminated the problem. (Keep in mind that in cars with excessive mileage, that the trailing arm bushings may also contribute to wheel hop, so your "mileage may vary", and replacing only these bushings may not totally cure your problem. However, many have reported that their hop disappeared when switching to other vendor's differential mount bushings only.)

Some Specs:

Installation is fairly simple and straightforward, following the R&R instructions in the 3rd gen. shop manual. You will need to have the stock bushings pressed out of the differential mount, and the new bushings pressed in, however.

I'm no longer on the list, so if there is any interest in these bushings, or in other bushings for the RX-7 suspension, let me know by e-mailing directly, and we'll see what we can do to hook you up. :)


From: Jim LaBreck (
Date: June 19, 2000

Front bushing set (8 major bushings, does not include the swaybar end links, although we'll be working on adjustable end links in the near future) is $485 + $12 S/H.

Send payment to:

Jim LaBreck
15725 NE 96th Way
Redmond, WA 98052


From: Steve Cirian
Date: June 27, 2000

>I know the original bushings were supposed to provide some
>compliance as a form of load activated geometry changing setup or something,
>but all of the bushings I've ever seen for anything are just hard bushings.

I have been doing a lot of thinking on this.

I don't think that the suspension bushings are supposed to flex for geometry change purposes. I do think the geometry does change - crank your steering wheel hard when parked and look at the tilt in (towards the direction of the turn) at the top of the wheels.

I think the only drawback to stiffer bushings would be that the ride may be a little rougher.

I think Jim LaBreck's bushings should be a great product. My only hesitation in sending him a check immediately is that I am pretty sure I need lower ball joints, which are supposed to require the repalcement of the entire lower A-arm. Those are ungodly expensive, somthing like $400 apiece (ballpark). The set of Jim's bushings for the front A-arms, with shipping, is a little under $500.

Since I am also going to get Jim's complete set of bushings for the rear as well, and probably going to get the M2 rear bits, I am looking at over $2K worth of parts.

Glen from New Zealand can get a bearing-based complete suspension replacement that includes pretty much everything including new A-arms. The price depending on exchange rate is about $4500. See:

I need to do the math and figure out exactly what I would spend doing my suspension as a mix of LaBreck, M2, and Mazda Comp parts and compare it to the bearing-based suspension kit.


Date: Tue Jun 27 2000 - 14:10:16 EDT

The degree of compliance, durometer, flexibility in suspension bushings is of great importance. race cars have spherical rod-end bushings that have no compliance whatsoever. i can assure you that if you converted your 7 to a rod-end suspension you would be finding your teeth fillings in your lap. then you would either remove your rod-end suspension or sell the car. they don't work on the street.

As to alternative materialed bushings... today you can find material from which to machine bushings that spans the range from buick electra to sherman tank. the crucial key as to whether you will be happy after a significant expenditure of time and money turns on the fine point of just where the material falls on the compliance/flexibility scale.

In short, you better know just what you are buying or you might just trash your car's ride characteristics and performance.

I say performance because too stiff a bushing decreases stick on anything but a glass smooth surface.

Having plotted the entire suspension dynamics of the (3) rx7 i can tell you it is almost perfect as to camber gain etc. consequently, you don't need to run huge spring rates and brass bushings to band-aid a lousy suspension geometry like most other "sportscars."

This is not to say that our cars won't benefit from a modest increase in bushing durometer, but the keyword is modest.


Date: Mon, 12 Apr 1999 09:54:03 -0500
From: "Eng, Cary" (

FWIW, Mostly Mazda's complete bushing "kit" is a hair over $700, and that includes the cool blue-anodized, heim-jointed rear locating arms. Actually it's not really a kit at all since they sell each bushing set individually. But the pieces they have replace the upper A-arms, lower A-arms, rear toe control links, differential mount, and a bunch of other places I can't recall off hand. They also have some cool heim-jointed adjustable rear toe-control links, but I didn't factor those into the cost. I think this is the kit I'm going to go with, but I just wanted to know all my options before I ordered the set.


Mazda Comp has stiffer rubber bushings than the stock ones, but does not carry the urethane suspension bushings.


Date: Sun, 29 Mar 1998 09:49:11 -0800
From: Spencer Hutchings (

Mazda Comp sells bushings that they say are 40% stiffer than stock. I'm getting ready to do mine. By getting ready I mean I read the prices in the catalog and had a stiff drink. They are not cheap. Tri-Point will install their own set of custom bushings, I think they are even more than the Mazda Comp. bushings though.


Date: Tue, 17 Mar 1998 21:44:35 -0800 (PST)
From: "M. Pacpaco" (

Try check out Prothane at That is off the top of my head, I know their phone number is 1-888-PROTHANE.

Or you can check out Energy Suspension, I dont know their number but check out Sport Compact Car or Turbo for their number.

My only complaint about the urethane bushings is that they are kinda brittle. I dont know if I had over tightened the endlink on my sway bar or not but within a couple of weeks after installation, one bushing out of four on the endlink was hammered. I gotta order a replacement one for .96 cents. It could of have been the washer that capped the bushing, but once it started cracking, it broke thru in a matter of days. When I replace it, I gotta make sure that the washer is smooth. Yet it is almost impossible to overtighten the bushing because it starts to bulge out like crazy once you get it snug.


Date: Mon, 30 Mar 1998 13:16:09 -0800
From: Dana Bourgeois (

OK. To complete the discussion of this subject, here is what I found out by calling Prothane and Energy Suspension - the two largest bushing manufacturers in the US.

Prothane announced parts for the 3rd Gen but haven't started the design process. Not enough volume they say. They only look at the US sales numbers and with Hondas flying out the dealers in large numbers they don't have the time to handle Mazda. The guy I talked with said his name is 'Fred' and he was definite about it. No plans to produce.

Energy Suspension doesn't even have part numbers for RX-7s past 1992.

I haven't tracked down a phone number for Mazda Comp or Mazda Speed so I don't have any information on those companies. I will talk with Mostly Mazda tomorrow and get the scoop on what Brian can do. If anyone is interested, send email and I will return mail a synopsis of what he tells me.


Date: Fri, 15 May 1998 15:09:27 -0700
From: Dana Bourgeois (

I searched and couldn't find ANY bushings for 3rd Gens from US OEM houses. They make 1st and 2nd Gen (so the RX7 is listed in their 'application guides' as being available) but even though there were some announcements, no one is making them.

Several list members sent mail during my search to say that Mazda Comp and Tripoint are about the only commercial sources. I talked to Brian at Mostly Mazda (Concord, CA) and he makes a brass bushing for his race cars but doesn't recommend it for the street. A couple of other kind souls mentioned they either had the expertise or knew someone who did and were thinking of making a batch for the list. I haven't heard anything more.

Turns out my problem was NOT the bushings so I haven't followed up on my original queries. If people are interested, I'll dig up what I have and post a summary.

Below is unconfirmed information - it may be inaccurate:

A complete set of bushings from Tripoint cost about $1600. I heard that Mazda Comp is about half that. The Mazda Comp are elastomer with twice the rigidity of stock (which would make them stiffer than stock for maybe half their life?) while the Tripoint are plastic instead of rubber.

Bushings are something that engenders intense interest on a regular basis and there doesn't seem to be a good answer for less than a premium price. I think if we keep our cars long enough then we will ALL need these parts. If anyone finds a source of bushings (not the elastomer ones) at a reasonable price, please post the source.


Date: Tue, 31 Mar 1998 19:01:20 -0800
From: "Derek Vanditmars" (

I have searched high and low and have come up with the following as available sources:

    --Mazda Competition Parts (800-435-2508) sells heavy duty rubber
      bushings that are 40% stiffer than stock.

    --They have most of the bushings for front and rear, but not ALL of them
    --If you want to order a catalog, give Ben or Tim a call at CSI
    --I can also email a scan of the bushing section and pricing of
      their catalog, (ask an ye shall receive, state your preferred image 
      file i.e. jpg,bmp...).

Performance Suspension Technology.
    --They do not do any of the other bushings

The following is a list of other people I have contacted and did not find

701 Pine Tree Road * Danville  PA   17821
 http//  (717) 672-9413 or (800) 903-9019
    --I checked our books, but have no listings on a 93 Mazda, sorry.  Laura

Suspension Restoration Parts Co.
     --I have not heard of plans to make '93-'95 Mazda RX-7 bushings.  You
       could contact Energy Suspension at, and express
       your interest.

Energy Suspension
    --Not available, no plans to make then either

    --Not available, no plans to make them either

A-ARMS (and ball-joints, dust-boots, etc.)

polished A arms

My car's A-arms shown above were polished, and have Unobtanium bushings pressed in. --Steve


From: Steve Cirian (
Date: September 17, 2000

The ball joints in the front A-arms are not replaceable. You have to buy the whole A-arm, at several hundred dollars an arm, even with MazdaComp's discount. If anyone knows otherwise or a vendor comes out with a replaceable ball-joint, please mail me.


Date: Wed, 27 Sep 2000 11:00:38 -0500
Subject: (rx7) [3] Front A-arm Dust Boots

Mazda dealers will insist that they do not sell the lowers separately from the A-arms and that you would need to buy the whole arm, at several hundred dollars. Ouch!!! Be carefull when removing the arms so you do not poke a hole in the dust boot.

I might buy the used arms from the car that Michael posted as being parted out, if the dust boots are in good shape.

Otherwise, if I can't find a good set of used ones through the Mazda recycling place, I may try patching the hole with a bicycle inner tube patch kit. As little as I drive the car, it would probably last a few years.


From: Tony (
Date: September 27, 2000

I think they do sell both the upper and lower A-arm dust boots.

First I want to make sure we are talking about the same thing. I am referring to the round black rubber piece that is filled with grease and sits at the outside edge of the upper and lower A-arms. It is held onto the A-Arm with a nut and a cotter pin goes through the nut. Is that the part you are talking about?

My screwdriver slipped when I was trying to pry the shock out of my 3rd gen and it cut a hole in that piece and grease oozed out so I knew I should replace it. I called my local Mazda Dealer and talked to a guy have I dealt with several times in the parts dept. He could not figure out the part I was talking about over the phone so he faxed me over a page with a picture of the front suspension taken apart and all the part #s listed.

Part numbers:

Upper dust boot 	#34-213 
Lower dust boot		#34-313B
New nut 		#99923-1400
New cotter pin		#99221-3025

I should have just got the pin at the Home Depot, as it was around $3.00 even at the discounted price the parts guy gave me.

You need to get some high temp grease and pack it in there and there is a snap ring that comes with the boot to keep it tight around the a-arm stud.


From: GT-C

Damn Mazda!! I gave them the part number off of the web site and they didn't know what to do with it. Said it didn't exist. I happened to be over at Mazdatrix and asked them and they looked it up on their micro-fiche and found it to be "FD01-34-313" no B on the end like on the web site. After looking at the micro-fiche from the 93, 94, and 95 I found they only put the part number on there for the 93's (with the "B" on it). The 94 and 95 version don't have a part number. The computerized version the dealer uses doesn't show a part number for mine 94 at all. Anyway after giving them the "FD01-34-313" number I now have two new boots on the way.


From: Max Cooper (
September 27, 2000

I don't know if these would be at all applicable, but Energy Suspension makes generic dust boots for tie rods and ball joints:


From: Tom Jelly (
Date: September 27, 2000

I'm sure you can find the joints somewhere, maybe a Moog catalog? It may ot show in a Napa catalog, but I'm sure you can get dimensional data from the manufacturer.


From: Mark Valskis (
Date: September 27, 2000

You could go to the local autoparts store to see if they had a "universal" boot that would fit. I know I have seen several at Autozone.


Toe Link Assembly

Date: Tue, 19 May 1998 02:23:16 -0400
From: (Chris Sychlovy)

If you suspect both the inner and outer bushings are bad, then it may be worth getting the "toe-link assembly". Even if only one bushing is bad, it saves the installation headaches. In addition to that, Mazda redesigned the rear toe links sometime late in '94, early '95. Only the newer, and presumably better, toe-control links are currently available... sorry, I never got a price.


Date: Wed, 21 Mar 2001 09:05:38 -0800
From: "Ulen, Robert S" (

The toe-control link's design was changed with the 1995 model year. Instead of having a threaded turnbuckle rod that screws into female tubes, the turnbuckle is a threaded tube that screws onto threaded rods which contain the two pillow ball and pillow bushing. Don't know why Mazda changed the design.


Date: Sun, 1 Apr 2001 08:50:24 -0400
From: "David Ieroncig" (

I was in need of the wheel side spherical bearing/bushing for the rear toe-links and my local Mazda dealers (parts departments manned by adolescents and/or grumpy old men)were unable to find a separate part number for them, therefore implying that I needed to purchase the entire toe link.

I ended up ordering it from a reputable Rotary vendor.

The OEM Mazda Part # is FD01-26-230



Why does M2 make and sell toe links that they advertise are better becasue they use solid heim joints when that's what the stock units have??? Also, the stock ones go one better by providing dust caps to protect the heim joints. I guess if you actually have bad toe links the M2 units are less expensive than the factory ones, but I don't see any other advantage. they both adjustable (obviously).


Date: Mon, 19 Mar 2001 16:08:35 -0500
From: Gordon Monsen ( Subject: Re: (rx7) [3] Question About M2 Toe Links

Brian Richards at M2 says the stock toe links (and trailing links) use rubber bushings. His site is quite clear on the matter. I, unfortunately, also thought the stock car used rubber bushings and installed the M2 toe links and trailing arms. The car seems much more stable and there certainly seems to be less flexing. (imho) they are also much better made than the stock units. Will someone who still has the stock units comment on this? -gordon


Date: Mon, 19 Mar 2001 19:25:08 -0800
From: "Jim LaBreck" (>)

The answer to why there are no bushings in the kit for the toe link is because the OEM toe link has pillow ball (Heim) joints which allow a far wider range of movement than a standard bushing. To put a bushing in place which only rotates in 360 degrees along a single axis would cause the suspension to bind. Since the Heim joints are already metal on metal, unless there is excessive wear, there is no reason to replace them because there cannot (by design) be any slop in the joint when it is in good condition.

Now the M2 toe links might be a cheaper replacement than new OEM pieces, but they are no different in function or adjustability. They look nice, they *look* stronger, but they do not actually do anything that the OEM toe link does not.


Date: Tue, 20 Mar 2001 02:26:48 -0500
From: Wael El-Dasher (

I have been following this thread with great interest since I didn't know what the benefit of the M2 Toe control was, but like Gordon, I do "feel" the difference. Since no one has an explaination and everyone just speculated so far, I asked Brian to explain it to me. Below is his explaination.

>While both ends of the toe links do indeed have heim joints, both of which
>are the same diameter, the inboard joint is incapsolated in a rubber
>This bushing becomes very compliant due to the considerable forces to which
>they are subjected. Any amount of compliance in these bushings will result
>in considerable toe changes in the rear suspension. The most prominent
>example of this is during trail braking upon corner entry. The "toe out"
>condition created by the bushings compliance to the braking forces creates
>an unstable "snap oversteer" feel. By eliminating all of the compliance in
>this area the handling is much more stable and predictable.

Of course, like most have already noted they are better made than the stock unit they replace, and my tech finds them easier to adjust than the stock toe control. Having bought the very first pair that Brian made I can vouch for their durability so far. They are a great replacement and would recomend them as a handling upgrade.


Date: Tue, 20 Mar 2001 18:54:04 -0800
From: "Derek Vanditmars" (

Well boys and girls, I had a look in my spare parts bin and the inside toe-link pillow ball has ~1/8" of rubber between the pillow ball joint and the outer casing for the complete bushing. So there is some give with this pillow ball / bushing assembly. I did not have an outside toe-link pillow ball to look at, so I will not comment on this one.

Jim is correct in that a pillow ball joint has no play, but the stock inside toe-link pillow ball is encased in rubber, allowing the entire pillow ball to move relative to the toe link

In addition I did not see any special seals to keep dust/dirt out of the pillow ball either.


Date: Tue, 20 Mar 2001 02:11:27 -0800
From: "Max Cooper" (

I was just trying to figure out why Mazda would have put a pillow ball in rubber like this, and it seems more reasonable a setup than my first inclination led me to believe.

There are six "degrees of freedom". This is the standard term, but "degrees" does not have the usual meaning of a ranked scale -- each "degree" here is independent. "Kinds of freedom" would be a more intuitive name for these things, but I don't make up the standard terms. Thinking about it in terms of a whole car, here is a complete list:

Tx - translation on the X axis - drive the car forward and back
Ty - translation on the Y axis - move the car directly sideways, left and right
Tz - translation on the Z axis - lift the car off the ground and drop it back down
Rx - rotation about the X axis - body roll
Ry - rotation about the Y axis - pitch and dive from accel and brake
Rz - rotation about the Z axis - steering or yaw

A solid rubber bushing with the thru-bolt aligned with the X axis and a link aligned with the Y axis (aligned like the loe links), offers significant resistance in these degrees of freedom:

Tx - its bound in a bracket so it can't slide on the bolt
Ty - resists motion pushing or pulling along the axis of the link
Tz - resists motion moving the whole link up or down, without changing the angle
Ry - resists twisting the link about its axis
RZ - reststs swinging the free end of the link forward and backward

A ball joint suspended in rubber like the OEM toe link eliminates the Ry and Rz resistance, while maintaining the properties of a rubber bushing in the translational directions (most importantly Ty). As Jim mentioned in a previous post, the suspension would experience some binding if a "regular" bushing was used here. And Mazda was not crazy to suspend a ball joint in rubber. ;-) And M2 is not crazy to suggest that their rubber-less replacements offer some advantage over the stock units.


Date: Mon, 8 Sep 1997 03:40:23 +0000
From: "Dave Girvan"

This is for those of you with base, PEG and Touring 3rd gens...

I just installed a Cusco front strut tower bar on my '93 base model today. I can sum up my thoughts on this modification in one word: "WOW!!!" I was not expecting to notice too much of a difference after the installation. Boy was I wrong. The front of the car now feels like it was carved from a solid block of titanium, initial turn ins are crisper, the entire car feels much more solid when going over rough roads, I swear there is even more road feel! The install took all of 3 minutes. This was the only modification I did. Just to be sure I wasn't dreaming, I took the bar back off and ran the same roads again. That's when I really noticed how much better it was. Your mileage may vary, but for me, I'm completely happy with this mod. Most 3rd gen tuners and parts suppliers should carry this item.


Cusco Strut Tower Brace

I would echo Dave's comments. I bought one of the Cuscos also (pictured above on my car.) I did not think I would notice a difference on the street, maybe just at autoxes. But I did. Strongly recommended.

It cost about $160 - 180 (I got it on sale). The rest of them cost well above that. I don't see any reason to pay more (some were like $300!).

The Cusco has a polished aluminum center piece and blue mounting ends. The ends pivot on the bar so you can get it perfectly aligned with the holes.

It should install in less than 15 minutes. I waxed mine first, as well as the top of the strut towers were it mounted, and it still took me less than an hour.

Greddy is importing the Cusco brace. There was some confusion over this between Dave and Trey's messages, but Greddy does not make it, just imports it. So if you see a Greddy Cusco brace, this is more than likely what they are talking about. The Cusco has blue ends, and the Greddy (the one THEY make for a lot more money) has red ends. Cusco is a respected name in Japan, according to several people. The Cusco is available from Rotary Performance or Elite Motorsports, as well as others.



You can also either order a new R1/R2 bar from the dealer or possibly find one used.


Cusco makes a rear brace, and it is carried by Elite Motorsports. As Nathan said, it probably won't make any difference in performance over the stock rear brace. It would be more of a dress-up item, as far as I know.


I am thinking of making a rear strut tower brace, to save some weight there, as well as for looks. I am planning on using two 3/8" male rod ends, jam nuts, and an aluminum bar 3/4" square drilled and tapped for the rod ends. I think I may drill out holes through it to lighten it even more. --Steve

The parts are on order from Racer Wholesale (bar from local metal supply shop):

Part #	Description					Cost
EMR6T		3/8" rod end, right hand, PTFE liner	$ 5.26	
EML6T		3/8" rod end, left  hand, PTFE liner	$ 5.26
AUT-3800R	3/8" jam nut, right hand		$ 0.16
AUT-3800L	3/8" jam nut, left  hand		$ 0.42
		Aluminum billet bar, 30" x 3/4"		$ ????


Date: Tue, 14 Apr 1998 21:30:33 -0500
From: "C. E. Howell" (

FYI, Mazdaspeed makes a polished aluminum rear strut bar that looks to be about $110-120.

I wouldn't think drilling out (your homemade one) would hurt much. Look at the R1/2 front bar. By design, the bar only resists axial loads on it.


Date: Thu, 05 Feb 1998 01:05:36 -0800
From: Thi Nguyen (

Today I installed the Millen strut brace.

I had the Cusco brace before and the Millen one seems a lot stiffer. Besides the lower profile and no rubbing with the hood's heat shield. The car felt stiffer in the corner and less sensation of pushing. I just wanted to post my thoughts. I really only expected it to be cosmetically different but it really surprised me with the performance difference also.

Weight-wise, the Cusco is a bit lighter. I think because it's hollow rather in comparision to the solid Millen bar, which I believe was made with the stock R1 mount in mind (my main reason for switching).

Well, after driving around most of the night in my favorite corners to see if there were any differences. IMHO, the Millen bar is alot better.


Date: Tue, 13 Oct 1998 09:13:04 -0400
From: "Cassada, Lewis" (

I got the bar on Monday. It's a quality piece. The crowns are red which is fine with me (I've got a red car) but I guess you could paint/anodize/powdercoat them any color. The bar is highly polished aluminum...looks like chrome. It's really beefy, lots of mass to it. I was surprised to see that there is an adjustable eye-bolt at each end of the bar that screws in and out so you can get the bar to fit perfectly. A nut screws down the eye-bold to lock the adjustment in place. Then there is another bolt that goes though the eye-bolt and the crown to lock the bar and crowns together. I need to get and Allen wrench to get them a little tighter...I've got the "infamous" ASP intake tubes and the bar clears them (not by much) and it also clears the fuse box on the driver's side tower. Like I've heard most people say, I can "feel" a difference in the way the car handles in hard turns. You don't corner any can just feel what the car is doing a little bit better.

I won't be able to get pictures of it until next week. I've got a GeoCities website in the works, and I will put the pictures there. The bar was $79 + $7 shipping across county. I'm happy with it...I couldn't see spending $150 to $250 (or higher) for something so simple.


Date: Sun, 21 Feb 1999 12:47:48 EST

Due to the overwelming response to the Pettit Drag Launch kit Group buy I am posting the following Info for all the people who wish to know what the kit includes and what is involved in the installation. I hope this answers all of the questions i have been recieving. The benefits far outway work put into this installation.

The kit includes the following:

(2) Control rod arms with metal bushings that replace the stock ones that parallel the wheels

(2) Diff mounts (made out of a hard plastic)to replace the liquid filled ones

(4) Upper A-arm bushings (made out of hard plastic with metal inserts) to replace the rubber ones.

I have not used the 4 A-arm bushings yet because I am so pleased with the way the car is set up now, however after driving the car for a while now I am considering installing those as well, but i love the car even more now.

I did not have the rear end clunk noise. I can only imagine that the noise would most likely be from the Diff mounts or the a arm mounts, because these are the only components with enough play to make noise if they were worne.


The good news is that u dont have to remove the diff to do it. just remove the exaust, PPF, drive-shaft,and shields then the 2 main bolts that hold the diff. The diff will now swing down, (must remove the bolt that holds the e- brake cabls first). there are 4 bolts on top of the diff, remove them. the diff mount is now out. now for the fun part. u have to remove the liquid filled mounts. I destroyed mine, I heated the part with map gas to loosen the bushings (the rubber caught on fire) so then I just melted them out then used a screwdriver to remove a ring on the inside. once that is out u can use an all metal chisle to bang out the rest I found the 1/4 in. chisle from sears worked best. Once u have the stock liquid filled bushing out all u have to do is tap the plastic bushings in with a rubber malet. Mine did not come with any directions so u can benefit from my hardship. The Diff mounts come in two halves and bang in from either side (so each bushing is comprised of two pieces) They are two different thicknesses. the thicker ones go to the outsides of the diff hanger and the thin ones go to the inside. When I installed mine I didn't notice the diference. What a bitch it is to remove them once they are in, so learn from my mistake!!!! If u do not wish to ruin your liquid filled mount for fear u may not like the way the car is then i sugest u buy a diff mount from the dealer & put the Pettit bushings in it and just switch the mounts (much easier) however i do not know what that part costs. (knowing Mazda prob. a lot.) I know it sounds involved but it is very easy especialy if u follow my directions, (I wish I had these directions when I did it).

The controll rod arms that parallel the wheels are very easy and straight forward to install so I will not bother taking up any more space to write about them.

Please note that I have a touring suspension, your results may be different on the R1 & R2 but my car feels like an R1 now. This mod has been the best thing I have done to my car and my car is heavily modified except the suspension. It is so different from what I was used to. Last year my 60' times at the track were like 2.6 because of the major wheel hop. most often I would have to let off for fear of breaking something, now watch out!!!! This wasn't the only difference though, the car is more nimble steering response is faster and the rear end follows very nicely. The car is very streatable, my car is not a trailer Queen, it is driven daily, In fact I am gonna go drive it right now!


Date: Sun, 21 Feb 1999 22:45:04 -0500
From: "Shiv S. Pathak" (

I'm curius as to how the drag launch kit affects handling in non-drag launch situations. Looking at the drag strip performance of other excellent handling rear wheel drive cars, it almost seems as if good launching ability and great handling are nearly mutually exclusive. Whereas, live axled Mustangs and Camaros launch like champs but handle like turds. Any ideas?


Date: Wed, 29 Apr 1998 09:32:30 +0200
From: Bernd Kluesener (

Factory (stock) alignment (94 and 95, 93 assumed to be the same):


total toe-in mm (in)            1 +- 4   (0.04 +- 0.16)
max steering angle deg          inner  36 +-2
                                outer  32 +- 2
Camber   angle                  0 deg 6' +- 1 deg (1deg 30' max diff left-right)
Caster angle                    6deg40' (1 deg30' difff left-right)
Steering axis inclin.           14deg5'


total toe-in                    2+-4 (0.08 +- 0.16)
Camber angle                    -1deg13' +- 1 deg (1deg30' diff left-right)
Thrust angle                    0deg +- 0.8 deg

Note: The toe-in values are for stock 16 inch wheels. If you use larger rims you would have to make some changes.


Date: Thu, 9 Apr 1998 14:04:33 EDT
From: TriPointEn (

Alignment and having it done properly is probably one of the most important projects on your car. The alignment should be ( race set up ):

    Camber:  2.25 - 2.5 degrees of negative camber
    Toe:     in 1/32" - 1/16"
    Caster:  6 - 7 degrees

    Camber:  2.25 - 2.5 degrees of negative camber
    Toe:     in 3/8" - 1/2"


Someone mailed me this (sorry - don't remember who), I think it was from Pettit originally (it does agree with the 16" specs Jeff Witzer mailed out below). I would highly recommend Pettit, at least for autox. A lot of the local RX-7 drivers use their equipment. --Steve

                  |               FRONT                  |       REAR
                  |                                      |
                  |  Toe            Camber       Caster  |  Toe       Camber
Wheel Diameter    |             16"   17"   18"          |        16"   17"   18"
Street            | 1/16" in   -1.2  -0.9  -0.8  +6.0    |   0   -1.1  -0.3   0.0
Long Track Event  | 1/16" in   -1.5  -0.9  -0.8  +6.0    |   0   -1.3  -0.5  -0.2
Short Track Event |    0       -1.8  -1.1  -1.0  +6.0    |   0   -1.5  -0.5  -0.2
Autocross         | 1/16" out  -1.8  -1.3  -1.1  +6.0    |   0   -1.5  -0.5  -0.4

Keep rear thrust angle set to zero.


From: "Jeff Witzer" (
Date: 27 Nov 1996 02:20:51 -0000

According to Pettit Racing:

                   |              FRONT           |      REAR
                   |      Toe     Camber   Caster |  Toe     Camber
Street             |   1/16" in    -1.2     +6.0  |   0       -1.1
Long Track Event   |   1/16" in    -1.5     +6.0  |   0       -1.3
Short Track Event  |      0        -1.8     +6.0  |   0       -1.5
Autocross          |   1/16" out   -1.8     +6.0  |   0       -1.5

Of course these are only a starting point, you have to adjust tire pressures, weight distribution, etc.

I use the street settings on the street (surprise) and had my local Mazda dealership do it. I sat in the car while they did it (VERY important!) to establish usual angles and ride heights. If you don't do this, your camber and toe will be off and the car will pull. Also make sure that the tech does NOT correct for road crown!


Date: Wed, 15 Sep 1999 21:24:15 -0400
From: Victor Masch (
Subject: (rx7) [3][track] Chassis setup for 18" Hoosiers

A couple of months ago I inquired about optimal alignment for 18" track tires. Got a couple of intelligent replies (thanks), a couple of dumb ones, but no one on the list admitted using big wheels on the track. The consensus seemed to be that big wheels require less camber due to shorter sidewalls on the tires.

I changed my alignment from 1.2/1.5 to 0.7/1.2 degrees of negative camber front/rear, and bumped the air pressure from 32 to 35 cold. After three hard track days, the wear on my second set of Hoosiers is very even and quite minimal. This set was heat-cycled by The Tire Rack, which may also have helped. Now that I'm not vaporizing the tires, I'll try to fine-tune, using the tire pyrometer.


From: Nathan Freedenberg (
Date: Thu, 22 Aug 1996 16:23:34 -0400

>My question to the list (particularly you racer types) is what
>should I have the various alignment setting changed to (castor, camber toe,

I use the Yoko's particularly the RSII's. My track and autox alignment setting are:

		Front		Rear
Toe:		+1/16		0
Camber:		-1.25		-1.30
Castor:		6.4

I could not find any info on castor settings and set it to stock with out the tolerance that Mazda allows, +/- 1. My car has not had any suspension work as of yet and handles neutral on the track with 36# ft, 34# rr, for autox 38#ft and 34#rr seems to work best for the slow speed twisty convolutions we call autox on the cramped east coast.


From: (Todd B. Serota)
Date: Thu, 22 Aug 1996 14:12:53 -0700

Different tires (and suspension setup, for that matter) require different alignment settings to be optimized. I would talk to Yokohama if you're going to run their tires. Generally, Nathan's camber settings are what I would call good "comromise" settings for running track and street, but you might want more negative camber if you're just running track events.

My other comment is that Nathan's tire pressures (I'm assuming you've listed cold pressures) seem quite high, and out of balance. Now, granted, he's using 008 RS II's, whereas I used RS's, but I ran mine at 28 or 29 cold all around for the track and they worked bery well according to the pyrometer, which is the only valid test. Remember, just because your car handles neutrally doesn't mean you're going fast. If all of your tires are overinflated, your car may well be neutral, but you'll go a lot slower because you're using the center portion of the tire to much, to the exclusion of the tread on the sides. Finally, since 3rd gens are 50-50 front/rear weight distribution, the only reason to use higher pressures in the front would be if the car is oversteering, and you want to correct it (higher pressures in the front will make the front stick less relative to the back, thereby correcting oversteer.

Todd Serota


From: Jim Walsh (
Date: Fri, 23 Aug 1996 09:13:49 -0700

I agree with Todd that these pressures look unreasonably high for RSII's. I've run RSII's since mid '92. I run 30 pounds cold for autocrossing, but I could see going a pound or two higher on concrete (around here the courses are usually asphalt). I'm more tempted to go lower (like 28) than higher. Unless you're pushing a lot you don't need near that much in the front, and are thus reducing the size of your contact patch by 25%. For the rear, I think you'd be getting a little excess wheelspin both off the line and coming out of corners at 34 pounds. If you are pushing in the front, you might be entering the corners too hot and understeering through the corner. If your entry speed is correct, you should be able to use the throttle to balance the rear on the edge, then accelerate through the apex and out of the corner. The car's very well balanced, so understeer is usually caused by driving style rather than the setup unless it's overly goofy.

For Castor, I'd go for as much as the car will let you. I think your camber's about right. Todd thinks you should run even more for a non-compromise setup, I personally disagree. I wouldn't run any more than you're running now, and if you got stiffer shocks (or adjustables) I'd run even less. I run 1.2 all around with my Koni's and I don't want any more camber, either for autocrossing or the track. Note that like overly high tire pressures, too much negative camber can really decrease traction on your rear tires in a straight line or coming off a corner as the outside half of the tire will be clear off the road surface.


From: (mazdarx7)
Date: Thu, 22 Aug 1996 18:13:42 -0400

Mike, my set up includes coil overs also. Let me comment on your email to the list.

>I lowered the front ride height 3/4" and the rear by about an inch.

Why not even? You never want the front to be higher than the rear - it can be downright dangerous.

>My question to the list (particularly you racer types) is what
>should I have the various alignment setting changed to (castor, camber toe,

There is no perfect answer as it various for tires, events and tracks. I do road race only, use R1's and currently am running -1.4 in front and -1.1 in the rear for camber. I live by the pyrometer and believe that I will have to go slightly more negative in front. With regards to castor get as close to factory spec as possible. Toe is arguable. I prefer the smallest amount of toe out the machine can see in the front (.01 to 02 inch),with the smallest amount of toe in in the rear. This is to facilitate turn in.

John Levy
\93 Yellow R1/


From: "Christopher N. Keller" (
Date: Thu, 22 Aug 1996 09:41:04 -0400 (EDT)

Well, I have a set of Dunlop D40M2's in great shape (32 PSI all around). I may try to swap the front and rear tires and see if it changes anything. I bought the car used, so it has done this since I got it. I do realize that roads are grooved, but the car pulls on every road (even in my neighboorhood), so I am ruling out the road in non-highway cases. Alignment specs are:

Toe: 1/16" in
Camber: -1.2
Caster +6.0

Toe: 0
Camber: -1.1

Rear thrust angle set at 0.


Date: Mon, 18 Sep 2000 13:32:55 -0700
From: "Hoskinson, Jeff" (
Subject: (rx7) [3] Eibachs and Super R's continued

About 1 month ago I sent a post to the list saying I had too much oversteer with my new suspension set-up and I wasn't that happy with it compared to the stock R1 suspension. Well after 6 auto-x's in the past 5 weeks I think I have a good set-up now.


GAB Super R's
245/45/16 Kuhmo Victoracers
Stock sway bars and bushings

Starting set-up:

Camber -1.6 FR, -1.5 Rear
Tire pressure 32 F, 34 R

First impression, way too much oversteer, too stiff. Shocks 7 on front and 4 on rear, running on go-cart track.

Second impression, feels nice and stiff, Shocks same. Running on smooth parking lot. Inside of the tires are heating up more than the outer edges.

Final set-up

Camber -1.1 F, -1.2 Rear
Tire pressure 36F, 38 Rear

Third and final impression. Shock set on 4 F, 2 Rear. Running on go-cart track again, car isn't upset by bumps so much. Tires are heating up more evenly. Fastest time of day Saturday and Sunday:)

I think I'll run the shocks stiffer on smooth lots and softer for the slightly bumpy track. The higher tire pressure along with less camber seemed to help heat the tires up evenly.

I don't think Pettit's alignment specs should be taken too literally, every car set-up is different (I think they also use this disclaimer), so start somewhere and do some testing and then try adjusting for your style/set-up afterwards. You can have too much camber!


Date: Fri, 13 Jun 1997 17:44:10 -0500
From: tom (
Subject: Alignment Shop in Chicago

The alignment shop is called Right Way, near Damen and Irving. Supposedly they have the latest equipment. I will be using their services before the end of the month


Date: Fri, 10 Apr 1998 00:18:01 -0500
From: tom (

I had the dealer (Lakeshore Mazda) do it to my specs, only because I had to bring the car there to do the brake recall. Stupid move. I got the car back w/ tan door panels covered w/ greasy fingerprints. I told them to evacuate and charge the AC while it was there, because I replaced the condensor and figured since the car was there anyway. There must be a bad hose, because they said it leaked. I asked them why I was charged for freon then, because if it had a leak it would never have held a vacuum. Blank stares. I just left. (the parts people are great though, even started giving me a bit of a discount after I spent about 1K there)

I was told later by a trusted collision guy (Gordy at Unibody 18xx N milwaukee) to go to Rags (Regs?) for alignments- supposedly they have the best equipment etc. Near foster or Lawrence. call gordy @ 773-235-1334 for their #, I misplaced it.

I really think it would be easier to just buy the alignment equipment sold by racer wholesale and do it yourself, then you could change easily from race to street spec. I don't have any experience with that stuff though, and doubt it would be as accurate as a laser setup like they probably have at Regs.


From Grassroots Motorsports, March/April 1998, page 48. Author - Tim Green, owner of Automotion.

			Basic Suspension Adjustments

Suspension			Less Understeer		More Understeer
Component			More Oversteer		Less Oversteer

Front spring rate		Lighter			Heavier

Rear spring rate		Heavier			Lighter

Front anti-roll bar		Lighter, or adjust	Thicker, or adjust
				to lengthen arm		to shorten arm

Rear anti-roll bar		Heavier, or adjust	Lighter, or adjust
				to shorten arm		to lengthen arm

Weight distribution		More rearward		More forward

Front shock setting		Softer			Harder

Rear shock setting		Harder			Softer

Front camber			More negative		More positive

Rear camber			More positive		More negative

Front tire width		Wider			Narrower

Rear tire width			Narrower		Wider

Front tire pressure		Lower			Higher

Rear Tire pressure		Higher			Lower

Front track			Wider			Narrower

Rear track			Narrower		Wider

Front spoiler			Larger, or more angle	Smaller, or less angle

Rear spoiler			Smaller, or less angle	Larger, or more angle


I had this mailed to me, but don't remember from whom.

Adjustment            To Increase Understeer      To Increase Oversteer
Front Tire Pressure   Decrease                    Increase
Rear Tire Pressure    Increase                    Decrease
Front Wheel Camber    More Positive               More Negative 
Rear Wheel Camber     More Negative               More Positive
Front Springs         Stiffer                     Softer
Rear Springs          Softer                      Stiffer 
Front Sway Bar        Larger (Stiffer)            Smaller (Softer) 
Rear Sway Bar         Smaller (Softer)            Larger (Stiffer)

Whenever making adjustments or changes in chassis setup make only one change at a time and be sure the change makes an improvement. This way you can see the effect of each change on the car. It is also a good idea to record these changes.


Stephen responds to someone's request for info on how to make the car give better steering feedback. --Steve

Date: Wed, 24 Mar 1999 10:35:40 -0500
From: Stephen J Lee

>Is there a mod I can do to reduce the amount of power steering
>assist (or otherwise gain steering wheel feedback)?

Simply remove the power steering. When you parallel park, it's a little hard but you get used to it and your arms get bigger. But the feel is incredible. I can feel every little pothole. I can feel the tire lose grip when I try a 4-wheel drift. It really is worth it.


I had posted that the fender lips are not the best place to measure the ride height from, due to the fact that we do not know if the stock height is the same from front to rear. In general, you want the front of the car to be lower than the rear (I am not sure what the correct term is for this, but basically the front and rear of the car will have a different height at which the weight is concentrated, and you want the front point to be lower than the rear point, or else the car will be unstable and tend to lift at high speeds). Aanyway, on most cars, you would use the frame rails to do this measurement, since if the car's fender lip in the front was lower than the rear lip, and you decided to even the heights out, then you would be raising the front or lowering the rear, making the car unstable. This is all fine in theory, but David Beale actually got out the manual and found out that the fender lip measurement is OK, for the 3rd gen. --Steve


From: David Beale (
September 21, 2000

Ride height is actually measured from the center of the wheel to the highest point of the fender lip (as per the shop manual). They don't actually say what it should be, but they do say that:

    a) left and right should be within 10 mm of each other
    b) front and rear should be within 15 mm of each other

Because the wheel radius is a constant (I hope!!), fender lip to ground is fine. If you use different diameter wheels and/or tires front and rear, you must take that into account (measure to the centre of the wheel like Mazda asks and you'll be fine).

Date: September 21, 2000's in page R-6 of the 93 Service Manual. It doesn't have absolute values but left/right and front/rear height diff tolerances. Measure the center of wheel to high point at wheel well. The tolerance for left/right should be less than 10mm (0.39in) and for front/rear it should be less than 15mm (0.59in).


I would add that even though it is allowed to have the rear up to 15mm higher than the front that you probably want it even or to have the front 15mm lower than the rear. --Steve


Date: Wed, 15 Oct 1997 10:08:48 -0800
From: Dennis S Pedersen (

It amazes me how common it is for suspension-kit 'manufacturers', to just throw these kits together without any real thought behind it. Actually the kits you see in catalogs are generally made up of a mish-mash of parts collected from different sources and sold as a 'matched' kit. And we, the end-users, are no less to blame for not properly testing the parts and the effect they have on the car.

I remember I once bought a really 'cool' after-market sway-bar that was significantly thicker than the stock one, only to discover much later that it was actually _softer_ than the original unit it replaced! Why? Because of the different mounting points it used. I've also bought springs that had improperly matched natural frequencies that caused the car to 'porpoise' down the road. That's when the front and rear of the car move up/down in opposite directions after hitting a bump. A good setup keeps the car level.

Well, I finally got sick and tired of all the 'seat-of-the-pants' suspension tuning, read some books, got some help from my Mathematician/pseudo-Physicist brother, and wrote several spreadsheets that help you design the optimum suspension for your car, whatever your goals for it may be. I used to advertise them in Grass Roots Motorsports, The Wheel and North American Pylon, and sell them by mail order, but now I provide them free to non-commercial users over the Internet too. See the URL below. They don't help you with strut- or shock-valving, but they do help you select the best spring and sway-bar rates based on your car's corner weights, wheelbase, suspension geometry and intended use of the car. This doesn't absolve the users from having to think (and maybe that's good!), but it does provide users with a structured approach to modifying their car's suspension.

Anyone who wants to try the spreadsheets out can simply send me an e-mail requesting a password. The web-site below has all the instructions.

DSP Suspension Design Spreadsheets

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