Brake Upgrades

Last updated: May 26, 2004

Commentaries from the mailing list on:


From: Steve Cirian (
Date: September 13, 2000

Some questions to ask of brake kit vendors:

  1. Will these fit with my wheel diameter (16, 17, 18")?
  2. Will these calipers clear my wheels from a backspace standpoint?
  3. Will the ABS still work, or can it be made to work with some modification?
  4. Does the kit come with a new master cylinder, or does it work well with the stock one (i.e.- preserve the same pedal force and feel)?
  5. What parts come with the kit (e.g.- calipers, rotors, rotor mounting bells, brackets, SS lines, pads, speedbleeders, brake fluid, etc.)?
  6. Do these come with matching rears?
  7. Is the brake bias preserved?
  8. Will the parking brake still work (since it is part of the rear brakes)?
  9. How many pistons do the rotors have?
  10. Are the rotors cross-drilled, slotted, or plain? Are they vented?
  11. Do you have MMC or ceramic rotors as an option?
  12. Can I get the rotors cryo treated? Can you do it and ship me the complete kit?
  13. Do they come with dust/water seals/clips (not sure of the appropriate term)?
  14. Do they come with anti-rattle clips?
  15. What pads do you recommend on the street? Track?
  16. How much does the kit weigh per wheel (stock is about 24 lbs)?
  17. Will the new brakes work with the stock brake ducts (R1/2)? i.e.- will things still line up properly?

This is not a complete list by any means, but I have been thinking about buying a kit, and these are some of the questions I have learned to ask.




From: Steve Cirian (
Date: February 16, 2001

Some things to consider before buying a brake kit:


Date: Thu, 24 Jul 1997 20:11:31 -0400
From: David Breslau (

>Date: Thu, 24 Jul 1997 12:11:06 PDT
>From: "Jeff Witzer" (
>My local Mazda service tech (who is not a typical Mazda employee - he
>actually knows what he's talking about, has raced RX-7's, has been crew
>chief on an RX-7 and a Porshe 962 team, and has built 3 rotor
>engines)(breathe) recommends going back to stock rotors and Hawk Blacks
>again. The cross drilleds eat up pads and the stock rotor fade is
>better fixed with ducting than cross drilling. He likes the Blacks for
>combined street and track use... I have to agree.

Hi Jeff,

If you're staying with the stock rotors, I would definitely get them un-drilled. I know there's been some controversy over this, but as the stock front rotors are marginal mass-wise to begin with, removing more metal and putting in stress risers seems like a bad idea (IMHO). Good air ducting will definitely help keep the rotors from warping.

>I *AM* eyeing Pettit's Outlaw or PFS's Wilwood brakes, though. Maybe
>even building a dual 8-pot front caliper system. Those of you out there
>with the big brake packages, how do you like them, how much better are
>they, how available are various pads, do they fit with stock wheels (for
>events), etc.?

All of the commercial big brake kits for the 3rd gen I've checked out (Bear, PFS, Pettit, Stillen) *require* going to 17" wheels for disk/caliper clearance. These kits all use a rotor diameter of 12.75 to 13.1 OD x 1.25 wide, and when you couple that with adapted aftermarket (not purpose built) calipers, there's no room for standard 16" wheels.

>Would dual 8-pots per rotor be overkill? If I'm not getting into the
>ABS then my brakes are the weak link, not the tires, so what's the
>general concensus here?

Couple things to think about. The number of pistons used in a caliper depends on:

1) Pad geometry - a long thin pad (which, when used at the periphery of the disk, is the most efficient) needs to have the piston load distributed along its length to prevent localized bending. For such a pad, as many as four or six pistons could help.

Another reason for multiple pistons is to combat pad taper caused by temperature differential across the pad/disk interface. By grading the piston diameters across the length of the pad, the force can be adjusted to minimize taper wear (along the length, top/bottom taper could also be combated by piston placement).

2) How many pads the caliper uses - some of the newest Brembo/Alcon calipers use two or more pads per side of the rotor. The increased number of pad edges increases the "bite" on the rotor.

3) The total piston area - if you do change your calipers, make sure that the new ones have the same total area (+/- 15% or so). If your new calipers use too large an area, your master cylinder will run out of piston travel before the pads have moved enough. Too small an area, and you can't generate enough force.

Both situations result in upsetting the front/rear balance, too.

From a practical standpoint, I think that six piston calipers are about right for this car, when used with an appropriate pad. I don't like the stock front pad design, as it doesn't concentrate the material at the outer edge (a simple leverage issue). I also feel that for all but the pure racecar, only the front brakes need to be built up.

I wound up designing and building my own six-piston calipers, because I wanted to increase my braking power without having to buy wheels and tires. These are made to be a direct bolt in (no adapter plate required), and clear the stock wheel. The pad is a Wilwood GT 4000 style, longer and narrower than stock, and about 30% more area.

For rotors, I settled on a 12.4 OD x 1.1 width, equivalent to the BMW E36 M3 (whose braking performance is better than a 3rd gen). The very large rotors used by all the kits increase the un-sprung and inertial weight of each corner. This will compromise suspension and acceleration performance.

If you chose to try aftermarket brakes, check out the issues I've raised. Look for dust/water seals (pure race calipers are rebuilt frequently, unlike street calipers, so they may not have these). Factor in the cost of larger wheels/tires. At the least, you might just concentrate on doing the fronts only.

Let me know if you've got any questions, or if you disagree with what I've said - I welcome constructive comments!


Date: Thu, 24 Jul 1997 22:10:34 -0400
From: Nathan Freedenberg (

At 08:11 PM 7/24/97 -0400, David Breslau wrote:
>If you're staying with the stock rotors, I would definitely
>get them un-drilled. I know there's been some controversy over this, but
>as the stock front rotors are marginal mass-wise to begin with, removing
>more metal and putting in stress risers seems like a bad idea (IMHO).
>Good air ducting will definitely help keep the rotors from warping.

I'd go so far as to get them slotted. The slots take very little material away but allow for some out gassing. Jeff Krause (not a mazda owner, dabbles with BMW's) can slot them for you. He can be reached at

> All of the commercial big brake kits for the 3rd gen I've checked
>out (Bear, PFS, Pettit, Stillen) *require* going to 17" wheels for
>disk/caliper clearance. These kits all use a rotor diameter of 12.75
>to 13.1 OD x 1.25 wide, and when you couple that with adapted aftermarket
>(not purpose built) calipers, there's no room for standard 16" wheels.

I personally know the PFS kit will fit with stock wheels. Both Pettit and PFS have the 12.75" rotors. I am not 100% sure that the Pettit kit will fit but I just measured the width of the both calipers. The Outlaw is smaller than the Wilwood. That leads me to believe that it will fit under the stock wheel. Of course, YMMV so check with Pettit first.

Both of these calipers use the same pad. It's quite large, 4.75 x 2.78, and 0.8 thick. I have found the pad to be available in almost every compound Performance Friction, Hawk, and Porterfield build. >>Would dual 8-pots per rotor be overkill? If I'm not getting into the >>ABS then my brakes are the weak link, not the tires, so what's the >>general concensus here?

If your not getting into ABS then you can push the pedal harder. Find that point when ABS activation is imminent and that's using the brake to the fullest.

Adding big brakes does not decrease stopping distance. You are limited by tire. The stock brakes can lock up the wheel, it however cannot do it repeatedly. Adding good ducting will allow you to retain the stock brakes and get superior performance.

My ducting utilizes the R1/2 front spoiler. A collector was fabricated, and mounts using the stock spoiler hardware. Flexible *dryer* ducting is used to direct the air to a fabricated piece replacing the splash shield. The cool air is fed to the center of the rotor. I'll try to get some pics of the ducting I have quite soon.


Date: Mon, 15 Dec 97 07:52:50 -0500
From: "Linthicum, Sandy" (

  1. Use stock rotors from Mazda Comp or Porterfield ($80/each)
  2. Do not allow shops to use air gun to put on wheel lugs and have them properly hand torqued (overtorque warps them 2).
  3. Do NOT do a high speed fast stop and immediately come to a complete stop and sit. It does make a dam bit of difference what kind of rotor you have if part of it is sitting under the caliper, red hot and cannot cool down at the same rate as the rest of the rotor because you are sitting still. If nothing else, let the car slowly roll for several seconds before coming to a complete stop.
  4. Try the Hawk HPS street pad. It is more than adequate for street driving and gives minimum dust. It'll stop you from 150 to 0, not problem. If you are looking for track level performance (back to back stops as above) then go with the Hawk HP+ or Blacks. Anything more aggressive (like the Blue) are for the track only, your rotors would likely be worn thru before they got a chance to wrap.
  5. Slotting and drilling are to vent gas and dust and have no significant effect on cooling. Drilled rotor do weaken the rotor and make it more likely to crack. Both mod cost extra and can be done to any stock solid rotor.
  6. Use a quality DOT4 brake fluid such as Motul 600 or AP600 and bleed your brakes at least once a year (full flush of system)

John can comment, but in 13 drivers schools (about 40 hours of track time) with stock rotors I have yet to have a problem with fade or dust and have used Mazda stock rotors (HPS pads for the street, Blues for the track).


Date: Tue, 21 Apr 1998 17:53:09 -0400 (EDT)
From: Fritz McKellar (

Now I have been hearing a lot of discussion about upgraded brakes. I don't understand why the standard Farell/Pettit/KVR brake upgrade *with the proportioning valve* is not good enough. Why are people adding even larger rotors when that would really only increases the weight and the distribution of weight hence hindering performance? The additional torquing advantage of an even an larger rotor (ie: to fill a 17" wheel) can only be experienced at *very* high track speed (I can lock my wheels at close to 90 MPH).

I would still be inclined to say that even if you could take advantage of the extra braking ability at high speeds, the extra power required to accelerate then decelerate the heavier rotor will neglect the advantage. As I'm sure many will agree, the idea is to keep the weight down, and adding an inch+ diameter of iron to unsprung weight plus moving weight further from centre will have a negative effect on performance.

I have taken my RX-7 to the track repeatedly and with the proper pads and ducting, I have had no problem with the Wilwood calipers and 12.25 78 vane slotted rotors. My lapping consists of 20-30 solid minutes. A side note: my upgraded brakes are being pushed to the limit, as I was quite capable of frying my stock calipers (with race pads) on my first lapping excursion in the RX.

I have been experimenting with brakes quite a bit with KVR, I am one of their upgrade kit testbed, ( and have not had a problem with the Wilwoods at all (well, the pedal feel is not as good as I'd like, but the brake fluid pressure will get bumped up). I also run the two piece rotor...

The standard brake upgrade (at least KVR's) is plenty sufficient when there is a proportioning valve. One thing I noticed that many people with extra large brakes don't include a proportioning valve. I am sure the huge front calipers threw their bias right off (as my Wilwoods did). I tried experimenting with different pads but then initial bite on the front would suffer due to the weaker pad in front. The proportioning valve really brings the stock bias back, making the car much more effective and fun the drive. Much testing has gone into the valve, and I am now able to bring the front and rear rotors up to identical temperature, try that without a valve!

I'm not saying which caliper is better than the other, in fact, I know AP is a better brand. If a new buyer would ask me if an upgrade is in order, I would say the 12.25 rotor (which fit the stock wheel btw) with the accomodating caliper and a proportioning valve would be overkill for anything less than 100+ MPH straights at a track where the lapping sessions go into the hours. Otherwise the standard upgrade with valve, ducting, proper pads and fluid change can run for a longer time on the track than their motor would permit.


Date: Sun, 20 Dec 1998 20:24:39 -0500
From: "Shiv S. Pathak" (

To some racers, Wilwood calipers are cost-effective and replaceable. Unlike AP and Brembo units, the Wilwoods I have seen have no dust seals around the pistons. While not a big problem, they are not as maintenance-free as the OEM quality calipers. No big deal if you tear down and go over your braking system after every race. Wilwoods are also popular due to their availability, price, and model selection.

Unfortunately, Wilwoods are structurally far less stiff than the AP/Brembo units. If you have someone pump the brakes while you carefully look at the Wilwood caliper, you will probably see it flex. You would see no such flex with AP or Brembo components. There is a cost differntial, of course. A Wilwood 4 pot caliper costs $65-85 from Jegs. A comparible Porsche/Brembo calipers costs significantly more (around $300, IIRC) from a Porsche dealer. They are even more expensive directly from Brembo, from what I've heard.

Caliper stiffness is very critical in performance. A stiffer calipers maximizes pad life and improves brake feel/modulation. Whether it is worth the extra $$ is up to the buyer.

FYI, the stock aluminum, lightweight, 4 piston front calipers on the 3rd gen are very, very nice. You'd be surprised how many "high performance cars" use heavy iron calipers with floating pistons. The stock caliper's limitation is that they can only accept stock-size rotors (11.6"x.8"). The smallish stock-sized rotors can only store so much heat before fade becomes a problem.

The stock pad size is also relatively small compared to aftermarket alternatives. The larger the pad, the longer its life. No big deal on the street, but in an endurance race, pad life can be critical. This is why 6 piston calipers are popular in certain types of racing. They don't brake any better, but the pads can last 50% longer. Downsides: More fluid needs to be displaced. Inital "bite" is also reduced. It's a common misconception than a 6 piston caliper will "outperform" a comparable 4 piston calipers.

Only when we get into 8 piston calipers, does actual braking performance improve. This is because 8 piston calipers use 2 pads. Approx. 15% of all braking friction comes from the leading edge of the pad. Two leading edges-- more friction. Lots of pad area as well--- longer pad life. Cost a lot though...

As for rotors, Brembo units are very nice. Holes are cast in, not drilled in. This greatly reduces the chance of stress cracks. They also use very high-quality iron and are very thick (typically 1.1-1.25"). All things equal, a thicker rotor is stronger and more fade resistant. They are also expensive, no doubt partly because of their overseas origins. They are one of the best, nonetheless.


Date: Tue, 24 Aug 1999 21:55:31 -0400
From: Sandy Linthicum (

>I am going with Porsche GT-2 brake system with 15" rotors and
>wanted to know if their is already someone with this setup.

Way too much rotor for the 3rd gen. Adds lots of unsprung weigh and centrif. weight to the front wheels for no reason. 14 x 1.25 racing rotors with AP or equiv calipers will handle anything but extremely specialized endurance racing (you want pad 3/5 inch thick, etc so you do not have to change them over 12-24 hrs racing) unless you plan to add 500-1000 lbs of ballast to the car.

1999 Mazda RX-7 Type RS Brake Conversion

From: Lunar7
Quantity Part # Description Year
2 F124-33-25XA Rotor, Front 314mm dia x 32mm thick 99
1 F1Z4-33-23Z Kit, Brake Pads Front 99
4 F124-33-696 Pin, Pad Retainer 99
1 F1Z4-33-98Z Kit, Caliper Front Right Diff Bore 33.9mm/38.1mm 99
1 F1Z4-33-99Z Kit, Caliper Front Left Diff Bore 33.9mm/38.1mm 99
1 F124-43-710 Line, Brake Caliper Front Right 99
1 F124-43-720 Line, Brake Caliper Front Left 99
1 F138-33-261A Plate, Rotor Backing Front Right 99
1 F138-33-271A Plate, Rotor Backing Front Left 99
2 F124-26-25XA Rotor, Rear 314mm dia x 20mm thick 99
1 FDY1-26-43ZA Kit, Brake Pads Rear 93
1 F1Z4-26-98Z Kit, Caliper Rear Right 34.9mm Bore 99
1 F1Z4-26-99Z Kit, Caliper Rear Left 34.9mm Bore 99
2 F124-26-261 Plate, Rotor Backing Rear 99
1 99650-14070 Wheel, Spare 4Tx17 114.3/O=40 99
1 90620-17627 Tire, Spare T125/70D17 99


From: SleepR1 (Manny Lozano):

Your dealer parts counter won't have the parts number for the Type RS brakes. You'll need to go through Mazdaspeed Motorsports Development for the '99 Type RS brake parts.

Hard brake lines, parts F124-43-710 and F124-43-720 are not available from Mazda Japan. FWIW, both Brian and Tim of Mazdaspeed Motorsports Development say the current hard lines (from the US spec FD) will work fine!

I have the 1999 Type RS brakes fr/rr, and yes they require 17-inch wheels (including the spare).

The '99 Type RS pads use a different pad compound than the US spec versions. They're apparently "better" than the US spec pads, but I won't find out until I use them on track. Although the pad sizes are the same for the '99 Type RS as on the US Spec FD brakes, the front caliper M-springs are larger (wider). The only way to get the '99 Type RS front caliper spring kit, is to order the '99 RS front pads, which INCLUDE the larger M-springs. The '99 RS rears use the same size V-springs and shims.

I plan to use the '99 Type RS stock pads first to test them, then switch to EBC greens all around, and then to EBC reds up front and greens in back... With the front brake cooling ducts and hoses, I may be ok with either the stock pads or the greens all around, as the EBC reds (or Hawk blue/black for that matter), need to get really hot for those pads to work well...

I don't have any plans to upgrade the master cylinder. As far as I can tell the '99 Type RS caliper piston sizes are the same as US spec version front calipers...the Mazda Comp people didn't mention anything anyway?

Type RS fr/rr rotors are 12.4 inches in diameter. The front RS rotors are 1.25 inches thick. The rear RS rotors are the same thickness as US spec rear rotors. Both front and rear calipers are larger, with the fronts being thicker as well, to accommodate the thicker front rotors. The front RS calipers have larger lower pistons than the upper pistons.

As I mentioned above, the Type RS brakes are hard to pick out visually as a brake upgrade when they're mounted inside my 17-inch SSR Integral A2s...which is fine with me, since I like the Sleeper look (thus the username "SleepR1".


From: Manny Lozano

Track tested '99 FD Rx7 Type RS brakes fr/rr with Porterfield R4E pads fr/rr, Mazdaspeed Motorsports Development SS flex lines, and Motul RBF 600.

Wheels/tires used were:

8.5 fr, 9.5 rr x 17, 42-mm offset SSR Comp
245/45 fr, 275/40 rr x 17 Hoosier R3S03s (3 heat cycles)

9 x 17, fr/rr, 45-mm offset SSR Integral A2
255/40-17 Yokohama AVS Intermediates (3500 miles)

Track is Putnam Park Road Course, 10 turns (clockwise, 8 right-hand, 2 left-hand), 1.77-mile long course.

I expected to lap at 9/10th speed potential for 20 to 25 minutes x 3 to 5 sessions per day. The new brake setup did not disappoint. I was finally about to stay out the entire sessions, without pitting in early due to brake fade.

The larger brakes induced ABS early and I ended up flat spotting my front Hoosiers down to the cord despite the ABS electronics on Day 3 (Sunday). FWIW the Hoosiers were fairly used up after Friday's all-day sessions, and so they were questionable on Sunday.

After burning up the Hoosiers, after the first morning Sunday session, I switched to my road wheels/tires (I wanted to test those anyway), and finished the event on the SSR IA2s/Yoko AVS I's.

All day of Day 2 (Saturday) was wet, and I'm happy to report that the Porterfield R4Es are usable brake pads in the wet. The AVS I's provided good straight speeds, but did not provide much cornering stick in the wet, despite the 10-inches of full-tread depth contact patch all around.

In the dry the new AVS I's were about a click or two slower than worn Hoosier R3S03. I did need to get reacclimated to driving the car with same size tires all around, as the car turns in much more easily with power oversteer easily inducible when the secondary turbo reaches full boost.

One of the spectators was monitoring my lap speeds (without my knowledge), and he was surprised to know that I had been lapping at a faster mph average than his buddy (my A-student) in a '99 C5 Vette (quite modified). The spectator was excited to report that I lapped at a 79 mph average, while the C5 lapped at a 78 mph average. Converting mph to laptimes yields: 1:20.658 for me in my R1, and 1:21.692 for my A-student in his trick C5 Vette.

Sadly I was not able to break into the 1:19s (80-mph average) like I'd hoped.

In all the Type RS brakes fills my need for reliable brakes at the track with the convenience of standard parking brakes for daily driving use.

BTW, the Porterfield R4Es ARE usable on the street. I have not switched back to my road pads--EBC Green Stuffs--and I still have the R4Es fr/rr on the car from this past weekend's DE event. The R4Es' cold stopping power is great, and I plan to leave the R4Es on until my next event at Mid Ohio, next Wed/Thurs/Fri (May 8/9/10).

New Hoosier R3S03s are on order, as well as new Porterfield R4Es...can't mess around at Mid Ohio...gotta have brakes and tires for THAT course!

Yes, I think the R4Es are quite usable on the road. Cold stopping power is amazing and much better than the EBC Green Stuffs. Stab the brakes and the ABS doesn't have time to work as you'll squeal the front tires on dry pavement!

Dust has been minimal after having cleaned the wheels yesterday. I do expect some dust, as the R4Es are racing pads afterall!

You'll have to be sure to install the factory pad shims with your R4Es, as the R4Es do squeek a little bit. They'd squeal more without the shims, guaranteed! The shims are available from Mazdaspeed Motorsports Develepment as a front pad hardware kit. The rear shims are available by purchasing rear factory pads (sadly enough).

IMO, the R4Es are the ideal pad for FD enthusiasts who are regularly tracking or autocrossing his/her car during the motorsports season, but also drive on the public roads. The daily usability of the R4Es makes pad changes unnecessary at the track.

As for rotor wear, my rotors have been worn smooth, with no deep grooves left behind as would occur with Hawk Black compounds.

Cost is quite reasonable for the R4Es. $208 for a complete fr/rr set.

Porterfield has an explicit warning that the R4Es are not meant for the road. I found that after 3 days of hard use at the track, they are perfectly roadworthy pads, as I've been using them in stop'n'go traffic all this week.

OTOH Hawk Blacks are NOT usable on the public roads (go ahead--ask me how I know). There is very little cold stopping power, and rotor wear with cold Blacks or Blues is unacceptably HIGH!

Porterfield R4Es need to bedded in, so DO FOLLOW THE BEDDING PROCEDURE, as the R4Es do NOT come pre-bedded like Hawk pads do.

Now that I've discovered the R4Es are roadworthy, I'll probably leave them in during the season, and won't switch back to EBC Green Stuffs until this winter!

For those of you who've tried Performance Friction PF-90s, I'd liken the R4Es to the PF-90 compounds--race pads that are road worthy too!

BTW, my new Hoosiers have already been mounted on my SSR Comps (kept the old rears, as they still have some life left). Still awaiting the new R4E pads--I always run full pad thicknesses for high speed track events, and use the old pads as spares. Mid Ohio awaits!

M2 Performance Kit

Date: Tue, 12 Sep 2000 22:01:28 EDT
Subject: (rx7) ***New M2 Big Brake Upgrade***

I spoke to Jeff from M2 today. Their new kit is comprised of Wilwood 6-piston aluminum calipers that I believe weigh similarly to the AP calipers.

As I mentioned in a previous post, the kit includes calipers, 13" rotors, pads, SS brake lines, and brake fluid.

The stock 16" wheels WILL fit on this kit.

Upon initial testing, Brian Richards stated initial bite to be just as good as the AP kit. Information should be available on the M2 site by now. Retail is projected to be around $1700, but if enough people are commited, then as a group buy, pricing might be around $1500.

Crooked Willow Kit

From Crooked Willow's web site:


In the front: Massive 14" Brembo Rotors with 6-pot AP calipers...all for the same price as some of the "best" kits out there.

In the rear: Finally, a kit that compliments the front and preserves brake bias.

(18" wheels required, though some 17's may work as well. Call for fit information or to request your own custom setup)

858.775.4292 or e-mail

Movit Kit

Date: Mon, 13 Apr 1998 12:53:44 -0400
From: "James V. O'Brien" (

A while back I posted about being impressed with the Big Brake kit described on Steve D'Gerolamo's "Ultimate Garage" web site.

Despite already having a very capable Big Brake kit on my, there was enough technical information on Steve's site to convince me that their kit would be a worthwhile upgrade (I take my car to track events as often as I can, and I push it as far as I can - sometimes too far. So, while the brakes on our cars are outstanding for street use, I have had too much experience with their shortcomings under severe road course use).

After exchanging e-mails with Steve, I went ahead and ordered the kit (which, for those who have not checked out the site, is composed of Porsche-modified Brembo calipers and Porsche brake rotors - basically the brake kit on the Twin Turbo Porsche's with the addition of SS braided lines and an adapter to fit 3rd gens).

Just over a week ago I got the package from Steve. I will not go into the technical aspects of the kit component's design and the Porsche modifications - this is amply covered by Steve's site and if you are at all interested I strongly recommend you check it out. I WILL mention that the kit I received was of unequaled quality!

Also (did I mention?), I now have MONSTER brakes! I mean, my previous kit was great compared to the stock calipers - but this new set is out and out ridiculous! As an example, the pads on my Outlaw kit (which, BTW, are the same ones that are used with the Wilwood Superlite calipers) were much thicker and larger than the stock pads - I measured the contact area of the pads and it was 7.50 square inches. Well, the Porsche pads (yes, these components all come in nice boxes with "Porsche" written all over the place - those guys must be insecure) have 11.51 square inches of contact area! That works out to almost exactly 50% more surface than the already larger-than-stock pads in the Outlaw and Wilwood kits.

Another example: rather than the usual "two halves held together by bolts with spacers on them" construction typical of these other calipers, the Brembo calipers have complete right and left halves with flat surfaces where they come together. Also, Porsche, among other things, disposes of the "puny" 8 mm bolts that Brembo normally uses to hold the two halves together, and puts in 12 mm bolts!

Finally, the Brembo/Porsche caliper is about 1/3 larger than the Outlaw caliper! These things are really BIG!

Coincidentally, that was my only big concern - as the calipers are so wide that you worry about the clearance between the caliper and the back of the wheel. Steve has a regular line of kits made up and installed on BMW's and he told me that they often have to use spacers to gain sufficient clearance on those cars. That is not something I would have felt to comfortable with. My previous wheels (from Complete Custom Wheel) had had minimal clearance over the Outlaw calipers, and my polished street CCWs needed approximately 1/4" spacers to keep the bolts on the back side of the wheel from rubbing on the Outlaw 4000 series caliper! (Side note - I know that John Purner at CCW has changed the design of the center piece so that would not have been the case with the newer CCW wheels - but mine were his first design for the RX-7 and they did not have much clearance on the larger-than-stock Outlaw calipers).

Well, I finally got the "Ultimate" kit installed last week and things worked out perfectly. Both my street and track wheels fit without need of spacers of any kind. On my SSR Integrals (17x9 with 38mm offset) there is a clearance of approximately 5/8" at both the top and bottom of the caliper face. On the Kosei Seneka S5R's (same specifications as the SSR's) the clearance is tighter but still adequate, about 1/8" at the edge nearest the hub and about 1/2" at the edge nearest the rim. (I do not know what the situation would be relative to stock wheels or other aftermarket wheels. If you have any specific concerns, e-mail me privately and I will try to work out a way to determine if there would be any potential interference.)

I have taken some pictures of the brakes as they are installed on my car, and my friend Bill Gammon has been kind enough to post them to a web page. If you'd like to see what real BIG brakes look like, then check out this.

Finally, for those who might be interested in getting the best kit possible, let me mention the details on the cost. First, the price I paid you will not get! Steve made an offer for initial kits that carried a price of $2,250 - plus an additional $100 if you wanted custom scripting to replace the "Porsche" that normally comes on the outside of the caliper (it has Brembo embossed on the inside face). That is what I paid, and accounts for the "Ultimate" logo on my calipers (I thought this appropriate before the fact just from the technical description - after getting the kit I now know it is not understatement). Further, the kit was more expensive to do than Steve expected, so he will not sell any other kits at that introductory price (I and one other are the only ones to get this price). Eventually the price of the kit will wind up at approximately $2,995! This is what the kits for the BMWs are going for (there are also kits for Corvettes and Chevy Impala SS's, of all things, but I don't know what he is charging for those). I think that even at this price, the kit is a tremendous bargain compared to anything else available. HOWEVER, Steve's web site does list a current special on Big Brake kits of $2,500 and Steve has told me he will hold this price till August 1. So, if you are at all interested, I'd get in touch with Steve as soon as possible. Contact info for those interested:

Steve D'Gerolamo - The Ultimate Garage

Oh, one last thing. That bit about the custom scripting - sorry, but that is no longer an option. Seems it got to be too much of a hassle (the work on preparing the kit is actually done in Germany by the Mov'It company), and even the "Ultimate" scripting on mine was not the design we ordered. So they will not do it any more - henceforth the calipers come with "Porsche" written on them (BTW - "Mazda" and "RX-7" apparently would have presented copyright problems). If the "Porsche" is too objectionable, I think Steve can get some special paint so it can be painted over. Guess I'll just have to make do with the only set that is unique, darn! 8-P

I will be glad to answer any questions I can, but only those that are posted directly to me and not to the list as a whole.


From: "David A. Kovar"
Date: Tue, 18 Feb 1997 16:39:05 -0600

The Stillen cross drilled rotors are actually Brembos.....although Stillen may do something special to them.

Anyway, recently (in the last 2 months), I bought the Brembo cross- drilled rotors with the silver Cadmium(?) plating. They work great and look absolutely beautiful. I highly recommend them. I was able to buy them MUCH MUCH cheaper than through Stillen from a company called KVR Performance Products which is located in Canada [(800) 636-0854]. They ended up costing $160US for the front pair, $189US for the rear pair, and another $40US to Cadmium plating on all four rotors...for a grand total of $389US (not including pads).

Oh...and yes the holes do appear to be 'set in'.

Just wanted to let you know about my personal experience with them.


Date: Wed, 21 May 1997 17:44:19 -0400
From: Nathan Freedenberg
Subject: (rx7) [3] Brakes..Revisited (long)

I have made changes in my braking system yet again. With this post I will attempt to document my braking experiences so those who came after me can save some time, money and frustration. For those that save this type of post *I* deem it a keeper.

I started as most of us did with the stock setup. For track use I found it woefully inadequate. I first changed pads, using Porterfield R4 pads for both street and track. I found them to be better than stock but still lacking iltimate ability. There was still a tendancy to fade on track.

I then bought the big brake kit from PFS. This includes Wilwood Superlite (tm) 4 piston calipers, 12.75 x 1.25 in rotors, Performance Friction 83 pads, front only SS brake lines and all athe assorted brackets and hardware. I chose x-drilled rotors and the system flushed and filled with Motul 600.

The stopping power was phenominal. I thought I had reached braking nervana. The drawback was the pads squealed worse than any truck I've heard and they chattered so bad at times I thought pad material would just chunk off from the constant hitting on the rotors. One the track they were just awesome. One the street you had to be sure to warm every thing before getting in traffic.

X-Drilled I found was mistake. In track use they cracked after one day. After discussion on the list I went with a solid rotor. This lead to other problems. After track use there was a buildup on the rotor that could only be removed by turning. Leaving the track became an adventure as the buildup decreased the braking power to less than stock. It would get worn off in ~2k miles if I didn't have the rotor machined.

This now lead to another addition. I had ducting built that carried air from the slots in the R1 type spoiler to a custom made backing plate, dumping ambient air in the center of the rotor. Any minor fade problems I had before on the track were gone. On the street I had to be mindfull of when the brake application was. The rotors cool fast, especially in the rain when water is being dumped in the vanes.

Business then brought me to FL. While there I visited Pettit and chatted a good bit with Cam. He showed me a set of Outlaw calipers that use the same pad as the Wilwood Superlite. He showed some areas where the caliper was different and assured me the incessant chattering would stop. I bought them.

During the same time period I met an engineer that works on the race team at Raybestos. We discussed the problems I was having at length. His reccomendation was to replace the solid rotor with one that is slotted. We aslo discussed pad compounds at length and reccomended some different compounds. Perfermance Friction 93 or Hawk Blue. He also said he would try to make up a set of pads to fit my calipers with some experimental Raybestos compound.

I now have the Outlaw calipers mounted, using PF 93's and slotted rotors. The chattering is gone. The pads fit these calipers much better. The squeal is minimized. I rarely hear it on the street and every now and again on the track. There is no buildup of *schmutz* on the rotors. Braking power is better than it ever was.

I have a set of the Hawk Blue's and will experiment with them and the Raybestos compound at a later date.

I didn't mention dusting because frankly I don't care about it. I wax my wheels and the dust comes off easily enough.

I'll start experimenting with rear pads soon. I have a few defferent sets on hand. I have been using the Porterfield R4's for some time. The stock rear pads CAN NOT stand up to track use. They WILL fall apart.

I hope this helps someone.


From: Tuck (
Date: Wed, 09 Apr 1997 16:35:09 -0400
Subject: Re: (rx7) Cross Drilled Rotors

I am using a set of PowerStop cross drilled rotors that I got from PFS (cad plated FWIW, it mostly just keeps em from rusting until you put them on) and a set of Carbon/Kevlar street compound pads that I got from Mazdatrix.

Both products deliver different advantages. The biggest improvement I've noticed since I switched to the cross drilled rotors that I can directly attribute to them is that my wet braking performance is significantly more predictable. Prior to installing the cross-drilled rotors hard braking on wet surface when there was a lot of spray would cause one wheel to brake harder tahn the rest, probably because of water under the pad. Since I switched, this problem no longer exists. I have been using them for 7 months now, with no cracks on the cross-drills.

The pads are the things that are going to help your fade resistance the most. With these pads I've pretty much been completely unable to get them to fade under even the most ridiculous street conditions (IE multiple stops and heavy braking from 100+). They dust less than the stock pads, and the only time they ever sqeuak is in reverse when I pull out of my parking space after a cold night. Otherwise, they just don't. As far as I can tell, they don't eat into the rotors in any manner that is noticably greater than stock as things like the Hawk Blues do.


Date: Fri, 29 May 1998 12:58:48 +0100
From: Ned Morrell (

>Is there any better options than Mazda Comp's hardened rotors?

I called Carbotech down in Ft. Lauderdale recently re: their cryogenically hardened rotors. In short, they use a liquid nitrogen immersion process followed by a heat annealing sequence to harden the rotor. He claims to use Brembos or Canadian quality rotors, and wanted $144 each for the fronts, or $99 per rotor without the cryo hardening process. I have not tried them myself, but that may be an option for you, Carlos.

Has anyone from the FL contingent tried Carbotech's hardened rotors? The claim is 3-5 times longer life and less warpage.

Cool Tech

Date: Thu, 09 Sep 1999 20:48:43 -0500
From: David Bennett (

Metal Matrix Brakes are much lighter. (The Lotus Elise has 'em)

According to Cool Tech, MMC dissipates heat 5 times faster than Steel.

You'll never have to turn the rotors.


I was talking to Bob Lee at Stop Tech today (310) 325-4799. He said the problem was that MMC could not operate at hotter than 600 degrees. Steel brakes can operate at at 900. Even with the greater dissipation of heat MMC built up to the relatively low temperature (for brakes) of 600 degrees faster than it could be dissipated with the standard MMC compound they have been using. Very soon they are coming out with a new compound that can operate at a much higher temperatures and still be just as light. They will be releasing kits for the RX7 and the Miata. I have both so it is doubly interesting to me. Mazda went to a lot of trouble & cost to reduce unsprung weight in our cars with aluminum suspension pieces and light weight rims - there's a reason for that!.

There's room for interpretation, but every pound of rotational weight you remove is the equivalent of removing from 3-15 pounds of "stationary" weight. The equivalency factor is dependent upon where the rotating weight is located & whose figures you believe. In any case you get the most bang per pound by removing rotational weight. On my 280Z MMC removes almost 10 pounds per wheel even with much larger brakes.

A diet would probably do the most good for most of us. There's a reason jockeys are so small and light.

One thing no one disputes is that reducing unsprung weight allows your wheels to recover from a jounce quicker which means you are less likely to skitter around on a rough road and the wheels will stay in contact with the ground more for increased traction in real world driving.

Don't give up on MMC brakes yet. They can be made to work hard like the rest of us.

By the way. The present MMC brakes work wonders except in sustained racing situations. That means that most of us would probably be more than satisfied with the present MMC than a steel/cast brake system. Stop Tech is running some specials trying to sell out the "in stock" old rotors.


Date: Thu, 09 Sep 1999 19:33:15 -0500
From: "Shiv S. Pathak" (

I had to get an MMC rotor turned.


Didn't just heat soak. It cracked. Twice.

> There's room for interpretation, but every pound of rotational weight you remove
> is the equivalent of removing from 3-15 pounds of "stationary" weight.  The
> equivalency factor is dependent upon where the rotating weight is located &
> whose figures you believe.  In any case you get the most bang per pound by
> removing rotational weight.  On my 280Z MMC removes almost 10 pounds per wheel
> even with much larger brakes.

1 lb or rotational weight is NOT equal to 3, 4, or 15 lbs of static weight. SCC's technobable a few months ago attacked this rule of thumb. Turned out that, depending on where the weight is (how far from center of rotation), 1 lb of rotational wheel weight--even in extreme situations-- is still less than 2 lbs of static weight. And since rotors are closer to the center of rotation, rotational weight is even less of an issue. Removing rotational weight is good, no question, but the effects are often over-stated.

> Don't give up on MMC brakes yet. They can be made to work hard like the rest of us.

MMC is a very promising rotor material. I just think it needs more work to be effective and durable. FWIW, I've heard that the Elise no longer uses MMC rotors for some reason or another.

> By the way.  The present MMC brakes work wonders except in sustained racing
> situations.  That means that most of us would probably be more than satisfied
> with the present MMC than a steel/cast brake system.  

True, if you don't go to the track, MMC could be what you are looking for.

FYI, next month's scc project rx7 installment talks about the long-term performance of the MMC brakes.


Date: Tue, 21 Apr 1998 10:30:59 +0200
From: Bernd Kluesener

When I decided to upgrade the brakes on my '93 R1 (European version) I took the car to England to have a kit custom made - after having looked at the unbelievable crap that is sold by the various tuners in the US (Wilwood, Outlaw etc.).

The specialist company for this kind of work is AP Racing, a division of AP Automotive Products, a merger of Lockheed and Borg & Beck. AP Racing is the number one supplier of racing brake and clutch systems for Formula 1 (Williams Grand Prix, McLaren etc), CART (Penske etc), as well as countless other race and rally teams.

At the front, my kit consists of:

at the rear: Since there are no racing calipers with integrated hand brake function available, I only replaced the stock disc with:

All discs are of the grooved type. Grooves improve cleaning of the pad surface and result in a more consistent brake performance. Grooved discs have a much longer life than cross-drilled discs. Cross-drilled discs offer improved 'bite' and 'feel' and slightly reduce disc temperatures, but are less resistent to cracking.

The weight reductions compared to the standard brakes are 1.3 kg (2.86 lbs) per front corner and 1.6 kg (3.5 lbs) per rear corner.

Of course I use matching friction material for the brake pads and of course the brake lines have been replaced too.

Everything is optimized to fit Fikse FM/5 17" wheels. By the way, the wheels are another story. I mail ordered them from PFS a couple of years ago. They came in the following configuration:

Front 8.5x17, offset 37.7, tire 235/45-17
Rear 10x17, offset 44 mm, tire 275/40-17

Compared to the std wheels (8x16, offset 50 mm) this setup increases the front track width by 24.6 mm (close to 1 inch) and the rear width by 12 mm (about 1/2 inch). At the front, the outside tire wall moves approx 18 mm closer to the fender horizontally and 6 mm vertically (increased tire diameter). This is the reason why the front tire sometimes interferes with the fender (bump in corner). Apart from that, the directional stability, especially on uneven surfaces, suffered too much for my taste. Therefore, I ordered new wheel rims from Fikse and changed my wheel/tire configuration to

Front 8.5x17, offset 50.4, tire 235/40-17 (Pirelli P7000)
Rear 9.5x17, offset 50.4, tire 255/40-17(same).

At the same time, I had AP Racing make the above mentioned aluminum disc bells with a 6 mm thicker mounting flange (kind of a built-in spacer). This increases front and rear track by 12 mm which seems to be a very good compromise. The car now has exceptional directional stability, a very good balance and there is no tire/fender interference. Also, due to the new rear tire the transmission gear ratio and thus the speedometer accuracy are back to normal. It might be interesting for all of You that the Pirelli's are approx. 4 lbs lighter per tire than the Dunlops SP8000 PFS supplied. And You all know what reduced unsprung mass means for grip, shock performance and ride quality.


Date: Thu, 23 Apr 1998 09:35:35 +0200
From: Bernd Kluesener

Weight of the AP Racing kit for my 1993 R1.

AP 3720 caliper with pads and RX7 specific mounting hardware 6.1 lbs
AP 330 x 28 mm disc with aluminum mounting bell 11.9 lbs

>From:  Fritz McKellar
> Your Porsche rotor weight approx 15.3lbs
> Wilwood caliper weight  approx 13.1 lbs
> 15.3-13.1 = 2.2 lbs difference * 4 (for standard conversion to sprung
> weight) = 8.8lbs * 2 (for each side) = 17.6 pounds of extra sprung weight being
> carted around. Not to mention the extra centrifugal mass. Excuse my breath!


Might be differtent from above...

Date: Mon, 16 Aug 1999 17:21:45 -0500
From: "Shiv S. Pathak" (

I've been tooling around with M2 Perf.'s new AP Racing big brake set up for nearly 2 weeks. You guys may want to consider this set up as well. AP Racing pre-bedded Indy/Champ car rotors (13"x1.2" with 48 vanes) and AP 4 pot calipers (with recessed dust seals and rattle clips). Both the caliper and the rotor are lighter than their stock counterparts.


Date: Wed, 8 May 2002 10:54:54 -0700 (PDT)
From: Gene Felber (

Subject: (rx7)[3] Important issue with AP brake upgrades...and a fix.

Those who have forked out $2,500 plus for their AP "big front brakes" might be troubled (or pissed ;) ) to find out that the calipers sold with some of these kits, the AP 5200 series ROAD caliper, can be and have been fried on road courses that are hard on brakes. Courses like VIR, Road Atlanta, Summit Point, Pacific Raceway, etc. If you're hard on brakes like me, and have a decently powerful car, this may be an issue for you.

This has been noted recently by RX-7 folks who regularly track their cars (including those with brake ducting) as well as among World Challenge cars using these calipers. Piston seals will cook, caliper paint will blister, and pistons may get cocked in the caliper rendering the brakes useless and dangerous.

Okay, now that I've scared you, there is a fix, but it's not cheap. The fix is a set of stainless steel pistons that replace the aluminum units. This mod has resulted in 75-100 degree reduction in caliper temps. This is also what AP uses on their NASCAR-style calipers (and they use Ti on Le Mans stuff, big $$$).

The cost for these is $79 per piston, totaling $632 bucks for a pair of 4 piston calipers. Essex Parts, a US AP supplier, is going to fabricate these for me (and I'm going to buy 'em anyway).

PS- in case you are wondering what differnces there are between these road calipers and race calipers, note the following:

The 5200 series road calipers are painted, are two-piece design (i.e., not monoblocks), use street dust seals, low-temp internal seals, and thin wall aluminum pistons.

The race calipers are hard anodized, sometimes monoblocks, use high temp caliper seals, no street seals, and use thick wall aluminum, stainless steel, or titanium pistons.


Date: Tue, 22 Jun 1999 10:46:31 -0400
From: Tuck (

If you really want intense longevity out of the stock rotors, have them cryo'd. I thought it was BS until I saw it work. I have worked crew with reasonable regularity for the Rotary Performance ITA car here on the east coast (now ITS), and that thing would crack a couple rotors almost every weekend. Last season Bret had the rotors cryo'd just to see if it worked, and the rotors lasted the whole season without cracking.


Date: Thu, 5 Apr 2001 21:33:53 -0400
From: "kevin kelleher" (

It is real, and works, if done correctly. As a practicing Engineer, I have followed reports in various technical journels. The process is recognised by ASM, and has been tested with positive results by independent government agencies, like military, bureau of standards, etc. These are mostly industrial gears, tools, and cutter knife applications. I think improved wear life is most relevant, with more carbides mentioned, and increased hardness in some cases.

Most importantly, hard core race teams use it. When I bought replacement rotors from KVR, the tech guy noted that race teams they do business with use it with success.


The following diagrams of the front and rear pads are courtesy of Spencer Hutchings. These are for Hawk pads, but the dimensions should be the same.


Front brake pads


Rear brake pads


Had this mailed to me, possibly originated from the Corvette list? --Steve

This list of brake pads was compiled by Scott Griffith,, from his publication, "Building the Perfect Pony".

For the street - try Performance Friction CM-S compund or CM90

                                        cold hot        rotor appx.
                                        grip grip noise wear  price

PowrPad Carbon Kevlar                     A    A    D     B   $150

CC Motorsport Cool Carbon                 A    A    D     B   $130

Stainless Steel Brakes Carbon Kevlar      A    A    D     B   $150

Porterfield Carbon Kevlar                 A    A    D     B   $130

Performance Friction Black (CM-S)         B    B    B     A   $60

Performance Friction CM90                 B    A    B     A   $80

Performance Friction Red (CM80, 5180)     D    B    C     B   $80

Berformance Friction Blue (CM83, 5183)    D    A    D     C   $80

Braketech black 4000-1 street             A    B    A     A   $60 (N/A)

Braketech black 4000-3 dustless street    A    B    A     A   $60 (N/A)

Braketech red 2000-4 hard full race pad   D    B    D     C   $100(N/A)

Braketech red 2000-5 soft autox pad       A    C    B     B   $60 (N/A)

Onadime Carbomet Plus                     A    B    A     A   $30

Various semi-metallic (raybestos, wagner) A    C    A     B   $40

Hawk Brake Black Hawk Carbotic (HBC9000)  A    A    B     D-  $85

Hawk Brake HPS6000                        A    B    B     B   $85

Hawk Brake Blue Hawk Carbotic             To be tested        $?

Repco Metalmaster                         "                   $?

Performance Parts Inc. Kevlar             "                   $60


Date: Sun, 05 Apr 1998 22:03:15 -0500
From: Michael Avila

PADS Jammin Motorsports KVR Mazdatrix Pegasus Pettit PFS Porterfield Racer Wholesale Roebuck Mazda Rotary Performance Brake Warehouse
OEM (F) - - $ 76.53 - $ 59.95 - - - $ 58.38 - -
OEM (R) - - $ 95.25 - $ 49.95 - - - $ 72.66 - -
Bonez (F): BR400332 - - - - - - - - - $ 65.00 -
Bonez (R): BR400333 - - - - - - - - - $ 65.00 -
Pro-Friction 1 (F): 0603-09F - - - - $ 99.95 - - - - - -
Pro-Friction 1 (R): 0603-09R - - - - $ 79.95 - - - - - -
Pro-Friction 2 (F): 0603-99F - - - - $ 139.95 - - - - - -
Pro-Friction 2 (R): 0603-99R - - - - $ 124.50 - - - - - -
Porterfield R4 (F): AP331 - - $ 112.97 - - - $ 129.00 - - - -
Porterfield R4 (R): AP332 - - $ 98.67 - - - $ 99.00 - - - -
Porterfield R4S (F): AP331 - - $ 118.00 - - - $ 79.00 - - - -
Porterfield R4S (R): AP332 - - $ 98.00 - - - $ 69.00 - - - -
PFS Superlite (F): 1-BRK-102 - - - - - $ 150.00 - - - - -
PFS Superlite (R): 1-BRK-106 - - - - - $ 150.00 - - - - -
PFS HP (F): 1-BRK-103 - - - - - $ 135.00 - - - - -
PFS HP (R): 1-BRK-104 - - - - - $ 125.00 - - - - -
Hawk Black (F): HB155 $ 75.60 $ 75.60 - $ 72.00 - - - $ 69.12 - - -
Hawk Black (R): HB158 $ 51.45 $ 51.45 - $ 49.00 - - - $ 45.12 - - -
Hawk Blue (F): HB155 $ 80.85 $ 80.85 - $ 77.00 - - - $ 73.92 - - -
Hawk Blue (R): HB158 $ 57.75 $ 57.75 - $ 54.00 - - - $ 45.84 - - -
Hawk HPS (F): HB155 - $ 63.00 - $ 60.00 - - - $ 66.24 - - -
Hawk HPS (R): HB158 - $ 39.90 - $ 43.00 - - - $ 45.12 - - -
Rofren (F) - - - - - - - - - - $ 54.00
Rofren (R) - - - - - - - - - - $ 48.00
Rotex (F) - - - - - - - - - - $ 49.00
Rotex (R) - - - - - - - - - - $ 44.00
Motul 600 $ 10.95 - - - $ 9.95 - $ 8.95 - - - -
Motul 600 (qty 12) $ 118.26 - - - - - $ 89.00 - - - -


Date: Wed, 21 Apr 1999 17:35:10 -0500
From: brad barber (
Subject: Re: (rx7) [3] Performance Friction Pads

David Breslau wrote:

> Not that I'm getting a kick-back, but...
> I've used stock, Hawk, and PFC pads, and the PFC is my pad of
> choice.  Yes, they cost more, but:
> PF90's can be used on the track (never had them fade) *and*
> the street (no pad changes = less hassle).
> They last a long time (long pad life = lower cost).
> They are kind to brake disks (less hassle and cost).
> Not too much dust.
> Good modulation.
> Hawks, in my experience with the Blacks, eat rotors, dust madly,
> and don't last that long.  When I balance all the costs, the PFC's are
> cheaper.

I also agree with Mr. Breslau. I've had stock, stock Porsche, Hawk and PF pads on my car. I use the PF93 front (Mov'It/Porsche "Big Red" calipers) & PF90 rear (stock RX7) combination on street and track. Awesome performance, life, and rotor kindness.

The price on the fronts will take your breath away, but worth the price, IMHO, when all is said and done.


Date: Tue, 15 Feb 2000 16:22:59 -0600
From: "Brad.Barber" (

Use Performance Friction brake pads. NOT the Z model, but the track pads. They come in six different torque ranges, their dust is organic and non-intrusive, they are wonderful on your rotors, and they work on the street. I will admit they are noisy on the street, but my car is noisy, too, so who cares?


Date: Thu, 9 Oct 1997 17:34:23 -0500
From: "Jones, Trey"

Hawk HP + - These ate my rotors on the street. On the track I ended up going off track @ 70 MPH at Hallette due to brake fade.

Hawk HPS - Nice on the street. Requires more pedal pressure than stock but don't dust. Wow, were these scary on the track. They actually fade worse than the stock carbon pads.

Hawk Blue - These cannot be used on the street. My friend took .030" off his rotors in two weeks. These are awesome track pads. This is the first time I have been able to brake hard without fade.

Conclusion - I don't think there is a pad that is an acceptable compromise between track and street use. I was shooting for this with the HP+ and it was bad at both. Changing your pads for events only takes about an hour extra if you are already changing your wheels.


Date: Thu, 12 Mar 98 14:26:41 -0500
From: "Linthicum, Sandy"

>From: Ryan McDonald (
>I have a probelm with the rear disks only lasting 1/2 of what the front
>last. I run the HP+ pads all of the way around and I can not find out
>why they die before the front, I call Mazda Comp. and they said that the
>back should last about 2x as long as the front. Any ideas before I pull
>the rotor and change the pads.

Mine wear out faster than the fronts also.

Fronts do 80% of stopping. Rear pad surface area is about 1/2 what you have in the front which concentrates the wear into about a 1 inch groove.

Get rid of the HP+ on the rear for the street. Put them on for the track if needed. It takes the rears pads much longer to get hot and as a result you get much more action against the rotor when they are not up to their proper operating temp. I would suggest the HPS pad for the street, certainly for the rear rotors.

I found that even with hard track use, the Hawk 9012 Blues on the rear caused a fair amount of wear because they just didn't get hot quick enough.

My front rotors have almost no wear.


Date: Thu, 19 Mar 1998 15:27:04 -0500

Doesn't get much easier: Hawk HPS

Low dust, grip well, no squeal, no fade (during autocrossing).

BTW, HP+ are supposed to be more aggressive, but I only found them to dust a lot more.


Date: Fri, 6 Mar 1998 18:27:34 -0500
From: "David Ieroncig"

I bought the Hawk Blacks. However, I must say that I could NOT bear running them on the street. Tried for 2 months.

The squealing isn't that bad... actually good for us pseudo racers. ;-)

The amount of CORROSIVE brake dust that these pads make is too much. Leave in the morning for that half hour drive in for work with clean wheels and by the time you're home you've got more dust accumulated on the wheels than a month's worth with the stock pad.

One thing though... the switch from stock to Black pads is an unbelievable experience. Awsome braking power and fade resistance. The hotter they get the more it brakes.

At the track, I never had a problem with them. Come to think of it, I got the impression that they dusted less at the track... but what good is that.


Date: Thu, 09 Oct 1997 23:15:26 -0400
From: Tuck

I am using Porterfield R4S pads on my car, they have about 20k miles on them and are just shy of a year old - they are just about gone (1/4th pad left). I got them from Mazdatrix and put them on with new cross-drilled rotors I got from PFS. The rotors don't look like they've been eaten (and once you've seen hawk blues on the street - you've seen eaten) at all, if anything there is little visible wear - the chamfering on the cross drills is still virgin - with visible cad plating in the holes. I don't think these pads are especially abrasive at all.

>If I've just washed my wheels, about 15 minutes
>of normal driving turns them from silver to grey. Any "decent" stops, like
>a 60-15 or something where you NEED to use the brakes but not an all-out stop
>turns them dark grey.

I don't find that I have nearly this bad a dusting problem, and my wheels are (of course) a crystal white/pearl. Then again, the gaps in the spokes on the TII wheels are much smaller than those of the five spoke third gen wheel, which may well account for that.

Personally, my experience has been that they dust slightly less than the stock pads did when you use the brakes heavily. The dust is also noticably easier to wash off than it was with the stock pads. I get almost no squeal from them - usually if the car has been sitting for a day or two, the first time I hit the brakes in reverse that day they _might_ squeal - otherwise they never do. They were extremely fade resistant on the track, I never worried about my brakes even when I was diving into the corners while catching up with a 911T. And they certainly stopped the car - I am very sure that I was outbraking everything else in my group, because that was one of the places where I was catching people.

I should add that these were the pads that were on the PFS Miata when I drove it, and they did squeal occasionally on that car, so there is probably some other factor that determines whether they are going to squeal on your application.

Granted, from a fade perspective my car weighs less than a third gen and wasn't going nearly as fast (since with the way my car was running, squeezing 115 out of it on the back straight was something I only did once when my car was somewhat more cooperative than otherwise, I think 120 was about the best I could've done with the car running at 100%). But the pads are literally the exact same ones for the second and third gen cars (in front at least) if the second gen has the four piston calipers, so my experiences should be at least similar. I should, of course, also point out that the second generation cars come with excellent brake ducts from the factory, which may help things out a little as well.


Date: Fri, 6 Mar 1998 23:35:32 -0500
From: "Alan H. Beder"

I've had good luck with the Porterfield race compound. They are easy on the rotors and stop well. On the negative side they create a fair amount of dust and are fairly expensive. If you don't mind changing pads at the track the Hawk Blues stop a little better and are cheaper. Cool Carbon is no longer made and supposedly the compound is identical to the Porterfields.


Date: Sat, 7 Mar 1998 13:42:16 -0500 (EST)
From: Jim Child

I have become convinced that its best to use track pads on the track and street pads on the street. For me anything else is an unacceptable compromise. Street pads suck on the track, and track pads dust like crazy, squeak, and eat rotors at street temperatures. Pads are easy to change on a 3rd gen too, especially the fronts. Once you get the hang of it, it should take you about an hour (including wheels off/on) to do all four corners. This is also an excellent time to do a brake bleed as well. I change over the day before an event in the comfort of my garage and drive to the track with the track pads on. This is no big deal since its usually mostly highway driving with little brake usage. I then swap back to street pads the day after the event.

I have used both Hawk Blue and Porterfield pads on the track in my RX7. I have also used Porterfield pads on the track in my 968. Both work well for the track and I recommend both. The Hawks seem slightly more aggressive, but do not seem to last quite as long as the Porterfields. Whatever you do, don't use Hawk Blues on the street. I did for a while and boy was that a mistake. At street temperatures these pads produce a dust that is one of the nastiest substances I have ever encountered. Imagine ordinary brake dust to the power of ten. I'm still trying to get this crap off of my stock wheels.

For the street I use the OEM pads. I like their silence, lack of dust and rotor friendliness. You can probably find a cheaper pad with similar qualities though. I find it hard to believe that anyone really needs a pad more agressive than the OEM pad for street usage.


Date: Sun, 05 Apr 1998 20:41:31 -0500
From: "Ryan A. Gabel"

About the brake pads, I liked my Porterfield R4-S pads on my old Mustang. They needed just a little heat to start grabbing good, and never really wore down the rotors. However, these are their street/autocross pads. The R4 pads are for racing and will wear down rotors from what I've heard. The R4-E's are for endurance races. The R4-S's lasted me two seasons of autocrossing with probably a total of 40 events, and daily driving.

Some people also like the Carbotechs. I think that Alex Tziortzis was using these on his old Camaro.


Date: 07 Mar 1998 01:19:17 GMT
From: (Dean Smith)

I use Metal Masters on the track.

They are OK on the street but they rust if you expose them to rain and don't use the car for a while. Other than that I like them, just have to get used to them on the street. (No Fade Means Less Fear) (No Fear Means you are going to slow)


Date: Mon, 06 Apr 1998 17:06:09 -0500
From: Alex Tziortzis

If you want to do road track events (solo I, time trials, lapping sessions) do not use street/autox pads, you will melt them. Including the carbotechs.

Carbotech, though, makes all the pads for Hawk Brake. I believe the Hawk YP5 is what you want, it is the lowest heat rated race pad and goes to 1000 degrees. The carbotech kelated metallic pad is only good to 750 degrees and I know of people who have melted them doing lapping sessions. Bob Anderson also ran the R4 (porterfield/carbon metallic), I dont think those will have the heat capacity that you will need.

My suggestion is to call carbotech(I have the number somewhere), they are in florida, and talk to larry. Nice guy, and he will tell you all you ever wanted to know about brake pads.


Date: Fri, 17 Mar 2000 07:12:32 -0800 (PST)
From: Mort Albert (

Jason, I autocross regularly, and I have tried pads from carbotec. First let me say that their prices are very high. After a very long discussion I bought their pad that is the HPS compound Cryo treated. I think that it is the F compound. I was assured that the pad would dust less then the Hawk HP+ pads that I was running, they wouldn't fade, and that they had at least the stopping power of the Hawks.

I replaced only the fronts, and left the HP+ on the rear. After proper break in the first thing I noticed was that I had to push the pedal much harder to get the same kind of deceleration. My girl friend who co-drives at autocrosses hated them. She said that it felt like the car had no brakes. Another observation that I had was that my rear brakes were dusting like crazy compared to when I had HP+ all around. This only confirmed what I was experiencing while driving, which was that the rears were doing much more work than before. My only spin last season was under braking, no less, when I had these pads installed. The thing that put me over the edge was after a day of hot lapping at Nelson Ledges, which only has 2 major braking zones, the pads were screaming at highway speeds. It was totally annoying, and embarrassing.

I called and complained to the guy, and he told me that I must have something wrong with my brakes. I told him "ya, it was his pads" and replaced them with a new set of HP+ from mazdacomp. I would rather clean my rims every week then use those pads.


Date: Fri, 17 Mar 2000 13:37:15 -0600
From: Jon Drake (

I've used the Panthers and didn't particularly like them. I'd rather use the Hawk Blues or the Hawk HT8's. The HT8's had a very similar feel, but better grip than the Panthers.


Date: Wed, 6 May 1998 22:10:15 -0500
From: "David Ieroncig"

I was advised by Randy to buy the Rofren pads over a year ago. I went for them.

I have to admit that they were and are a little bit of a dissapointment.

Sure... they don't dust... however they don't bite well enough either. I broke them in for the lengthy period recommended, but they don't even seem as efficient as they stock pads!!

Is the fact that experienced these for the first time with my cross drilled rotors (less contact area)... I don't know.

With all due respect to Randy who seems to be really on top of things, I personnaly don't really recommend the Rofren pads.

If I had to choose pads for the street today... HPS would get the nod. (Largely based on my satisfaction with the Blacks on the track.)



Give Larry at Carbotech and ask for the "greens". He made me a nice set of pads and shoes for the ST. They dust up a bit and squeak but are pretty high CF low temp design great for Autox but fade in high temp use.

Call 954-493-9669 and talk brakes with Larry. He's got the Greens for autox, a street pad that squeaks less and Panthers for Road racing.



The Greens are *definitely* an auto-x only pad. You'll fade em on the street.. Allen, don't even think of em for any track event. Even on some auto-x courses you'd fade em.

I had em a good while ago on the Neon, and were awesome for auto-xing but were killing me on the street.

SSF compound is definitely the best bet for the street, very little dusting, good high, broad temp range.


From Per Schroeder

Per Larry at Carbotech:

pad 		temp range	usage
Green		0-700f		autox only (high friction .52)
SSF		125-900	street/autocross/light track (medium high friction .48)
Panther	175-1300	autocross (w/ warm up), heavier track use  (highest friction .56)


Date: Thu, 22 Apr 1999 16:34:38 -0500
From: "Jon A. Drake"

I now have experience with 4 different brands of pads at the track. These are my results:

Hawk 9012: Liked them very much. Good stopping power and I never got any fade. About medium in wear on my rotors. Lots of dust, but who cares on the track. No way on the street.

Hawk MT4: Absolutely devastating on my rotors! Completely wore the slots off my slotted rotors! Dust is red rust and almost impossible to remove if it gets wet. Sparks will fly from your wheel wells on these pads.

Hawk HT8: Liked them very, very much. No fade, even at Summit Point where I was braking from 140-145 down to 40-50 ... extreme braking conditions. They dust a lot, but it is easily removed. They also wear out faster than the Blues but operate over wider range of temps and are more rotor-friendly. Probably not good for the street.

Carbotech Panthers: An interesting pad. No fade at all even at Summit Point, but I went through an entire set of pads in two days! The stopping power is as good as Hawk 9012's but it is an even stopping power across the spectrum. The Hawk Blues bite hard at first, then seem to ease up. The Panthers don't bite hard but stop in the same distance. Probably will work OK on the street if you can live with the dust.

I want to try the PF's before I settle on a brand, but right now I lean towards the HT 8's.



You will need to engineer the size of the piston in the new MC to work with the increased number and size of the pistons in the calipers. This is beyond the scope of this site, at least for now. We would recommend one of the books available on this topic, such as "Brake Systems: Oem & Racing Brake Technology" by Mike Mavrigian, et al.

The normal upgrade here is the one from the Mazda 929. It will handle some of the big brake upgrades, which typically require a bigger master cylinder (MC).



Date: Tue, 14 Jan 2003 11:25:43 -0800
From: "Jim LaBreck" (
Subject: (rx7)(3) Interesting information on 929 MC upgrade...

I ordered a 929 master cylinder directly from Mazda to go with my big brake kit and was told that 929 master cylinders are no longer available new.

They are now selling remanufactured master cylinders, apparently, but at a lower price, with a $50 core charge. The FD3S master cylinder is acceptable for return, I was told.


From: albeder
Sent: Tuesday, January 14, 2003 12:40 PM
Subject: Re: (rx7)(3) Interesting information on 929 MC upgrade...

I bought a new one (#HG31-43-400G) through Mazdaspeed Motorsports at the end of December. It was brand new.


Several people are using the master cylinder from a Porsche. I will post which model # when I find out (or email me if you know).


Picture of SS brake lines (courtesy of Spencer Hutchings):

SS brake lines

Paul responds to a question on SS brake lines someone posed about SS brake line failures (several people mentioned that the older / non-DOT-approved lines had failed due to not having swivel connectors. This failure may have been due to the lines not being able to flex properly. --Steve

Date: Mon, 02 Aug 1999 16:39:37 -0400
From: Paul Foster (

If you must get SS brake lines I suggest you do 2 things:

1) Only buy from Earl's or some other reputable builder you know will test the parts under pressure and has a proven track record for quality stuff.

2) Make sure you get DOT-approved lines with the swivel connectors. Why? Let's say you do have a catastrophic brake failure on the street. Let's also say someone gets seriously injured. If the accident investigation reveals it is due to a 'racing' component you installed that is not DOT-approved then guess who gets the blame???


Date: Mon, 2 Aug 1999 14:14:58 -1000 (HST)
From: F8LDZZ (

Where did this thing about having a swivel fitting on a DOT-approved brake line? Does the Russell lines have swivel fittings? The Goodridge ones do not...

The problem with SS brake lines previously (Race only) was that when they failed, they failed IMMEDIATELY. No warning! This is why OEM lines were rubber - at least the rubber lines gave a bit of warning before full failure.

The DOT-approved lines have an extra lining (Teflon?) that made a more progressive failure. This is the only DOT requirement for brake lines.

Goodridge uses colorful heatshrink to keep abrasion down from the SS braid. Really has nothing to do with the DOT-approval...


Date: Wed, 05 Aug 1998 01:38:23 -0500
From: David Liberman

>Nope, they're tested to DOT levels, but aren't DOT certified. I saw ones
>from Pettit that were DOT certified, but really it isn't that important to
>me. I don't expect a cop to pull me over and give me a ticket for brake
>lines. :]

I hope they're top quality. If one of those lines shears, and causes an accident, say goodbye to your car and your insurance, and expect a lawsuit from anyone else involved, as well as an investigation from the local chapter of the feds. It's not worth it to save twenty bucks.

Before you think, "Oh, blow it out your arse, Dave", I have personally experienced the failure of an aftermarket steel-braided line, while driving my car back from Pettit last year. Not thirty seconds after I got off the interstate in Orlando, where I was really dogging it (I braked nearly into ABS from 80+ coming down the ramp), I pulled into a convenience store, coasted into the parking spot, and braked... but the pedal went to the floor. I grabbed the e-brake to keep from jumping the curb.

Turns out that the right front brake line sheared, at the caliper fitting. Eight hours and a borrowed stock line later, I was on my way.

The manufacturer of the lines acknowledged that they had a bad run of 3rd gen SS lines. They have since found the problem, solved the problem, and given me a new set of lines, which I have on my car now. They are DOT-approved Russell lines.


Date: Thu, 22 Jan 1998 01:03:54 -0500
From: (Chris P Sychlovy)

This may seem trivial, but the SMC Goodridge lines I bought from MazdaTrix looked a little off... the rears were very close, the fronts were missing the center fitting and were 1/2" short. It turned out I had received s/s lines for a 2nd gen :o

Depending on the manufacturer, the hexagonal fittings may or may not fit. These are either 17mm or 19mm, but some manufacturers use 11/16" or 3/4" which have to be filed down.

BTW, the 3rd gen SMC Goodridge lines fit without any kinks and did not require filing. The fittings on the rear lines did not have the dog leg that's supposed to prevent the line from pivoting around the banjo bolt... a nice feature of the Mazda OEM lines. Keep plenty of paper towels and old newspapers around and take your time... a botched job can spoil your day!


Date: Thu, 9 Apr 1998 08:06:59 -0700 (PDT)
From: Bill Geiger

I just installed my Pettit SS brake lines a few weeks ago, and they did not fit perfectly. The rears were a little tight, but the fronts were much more difficult, especially the center mounting point which was not the right shape. The new lines are hex shaped, while the old ones had one of the corners rounded off. I managed to get the clip on without any filing.


Date: Wed, 08 Apr 1998 19:58:31 -0500
From: Michael Avila

Has anyone out there installed the Pettit braided stainless brake lines? I just had them installed today, and my mechanic had one hell of a time installing them. Basically, they didn't fit properly (at the mounting points), and he had to do a lot of filing and modifying to get them on. I was told they were a straight 30-minute bolt-on item.


A few others said they had problems w/ the Pettit SS lines. --Steve


Date: Fri, 29 Aug 1997 20:00:08 -0400 (EDT)
From: Francois McKellar

Realised the problem at the track as well. While the stock master cylinder will not allow increasing the rear brake bias, you can install cheaply a proportioning valve on the line to the front brakes lowering the power to the front slightly. While this may seem a good way to increase the braking distances, quite the opposite is true as the rear will have more of a chance to reach peak torque power in synch with the front resulting in smoother and shorter braking distances.


From: Jeff Witzer (
Date: Wed, 05 Nov 1997 09:43:32 PST

I'm currently running Motul 600 race brake fluid. It is amber in color and runs $10/pint.

A good trick is to flush it with a fluid of a different color to tell when you're completely flushed. Super Blue (which is has a sister fluid which is gold... same everything except color. My BMW friends swear by it and it's cheap at $10/2 pint bottle.

For my next event, I want to flush with a different color fluid but wanted any advice the list could give before I just use the Super Blue.

PFS recommends the Castrol, but it's ridiculously expensive ($80/pint, I think). Indy teams use it so it's probably OK for me :-) (if it's compatible with our system).

I'm looking for something that's boil resistant, and has very good resistance to compressibility.


Date: Wed, 05 Nov 97 13:15:05 -0500
From: "Linthicum, Sandy"

Try Porterfield. I bought a case of the Motul 600 for about $100 (12 cans). This will get your cost down. Dry boiling point is close to the same for all the DOT4's. Use anything you want as well as DOT3 as long as you are SURE you will throughly bleed your brakes prior to each event with an unopen bottle of fluid (yea right). Wet boiling point is of more interest to me (since I've been know to be slack at times) and here the Motul is unequaled for 2 or 3 times the price. Its wet boiling point is about the same as the Ford heavy duty DOT 3 fluid when totally dry. On the other hand, the AP600 is also probably more than adequate.

I wouldn't worry about the color. Just get some Speedbleeders and run a full unopened fresh bottle of Motul through the system each time you bleed the brakes. As an alternative, you might inquire at Porterfield if there is a dye that you could add to trace the color if you are really worried about it. You cannot easily flush the entire system anyway since the brakes & clutch share the same fluid and the bleeders are on the top of the calipers. The fluid at the bottom tend to settle there so you just cannot get 100% out without a lot of trouble ( I mean, do you really want to remove and bench bleed all four calipers?)


Date: Tue, 24 Feb 98 07:25:23 -0500 From: "Linthicum, Sandy" >Trying to determine if I should put Dot 5 (Silicone)
>brake fluid in my car.
>Someone has told me that is shouldn't be used in ABS as
>it holds air and is sensitive to agitation.

NO, do not use silicone DOT5 with ABS. Return it and go with a quality DOT 4 like Motul or AP.


Date: Tue, 24 Feb 1998 14:42:15 -0500
From: Scot Kight

The real reason as to why not. DOT5 CAN (not always) eat certain types of seals in your ABS braking system. That is bad.

But that's not the worst of it. 5 + 3/4 do NOT mix. They form some kinda spooge in your braking system. Now the original poster said he had speedbleeders. Sounds great, but the only way to get all the fluid out is to pump the system till its dry. then use the normal method to draw the fluid through, and hope that none is left anywhere in the system. Speedbleeders dont give an advantage here unfortunately.

Speedbleeders CANNOT be used with lots of air in the system, they just dont work (read the documentation on them) With a mostly presurized/liquid system they work GREAT though, I have them and belive me, I know ;>

OK, if you know the ABS system seals won't be eaten, the old fluid is ALL gone, and you have a few friends to help in the initial bleed. DOT5 is a GREAT fluid. but if you are on the street, and live in reality, getting the 5 in there is very hard to do. You could go for 5.1 which is compatable with other normal fluids. but I would suggest a good DOT4. esp on the street, you NEVER see the temperatures required by the higer priced/DOT numbered brake fluids.


I didn't save the person's name who mailed this to me. Sorry. --Steve.

Thanks to Dave Zeckhausen :

Let's look at what the DOT ratings mean. The table below shows the MINIMUM wet and dry boiling points for DOT 2, 3, 4, and 5 brake fluid in degrees fahrenheit.

			DOT 2		DOT 3		DOT 4		DOT 5
Dry Boiling Point	374		401		446		500
Wet Boiling Point	n/a		284		311		356

The DOT 2 spec is for drum brakes and is obsolete. If you have any DOT 2 in your garage, throw it away! DOT 5 is for silicone brake fluid.

Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY!

That leaves DOT 3 and DOT 4 fluids. These fluids are compatible with each other and may be interchanged or mixed with no ill effects.

Let's look at some popular brake fluids and their boiling points:

Fluid				DRY	WET
 Castrol LMA DOT 3/4		446	311
 Ford Heavy Duty DOT 3 	550	290
 ATE Super Blue Racing	536	392
 ATE TYP 200			536	392
 Motul Racing 600		585	421
 Castrol SRF			590	518
 Performance Friction	550	284

Castrol LMA is very good at rejecting moisture and may be kept in your brake system for a couple years. The LMA stands for "Low Moisture Absorption". This is the minimum quality stuff that I would use in my Impala. It comes in plastic containers which do not have a long shelf life. Don't buy lots of this stuff at a time because moisture can make its way through the plastic containers.

Ford Heavy Duty DOT 3 is VERY inexpensive and is popular among racers because of its excellent dry boiling point. It absorbs moisture quickly, but the racers don't care since they change their fluid frequently. Comes in metal cans so it may be stored. I would not use this in my Impala for the street.

ATE Super Blue Racing and ATE TYP 200 are the same brake fluid in two different colors (blue and amber, respectively). BMW recommends this brake fluid for their street cars because it, like Castrol LMA, absorbs moisture very slowly. The advantage over LMA is that ATE has a much better wet boiling point. You can put this stuff in your car and forget about it for a long time. An excellent choice for a weekend track car which also sees regular street duty. Comes in metal cans. This is what I use in all my street cars.

Motul Racing 600 is a very exotic and expensive synthetic fluid with high wet and dry boiling points. I use this exclusively in my race cars. Too expensive for the street and requires frequent changing due to its hydroscopic nature. Sold in plastic bottles.

Castrol SRF is a hyper-exotic and hyper-expensive brake fluid that is generally used by wealthy Porsche owners at track events. I've seen prices of $78 per liter for this stuff. It is not suitable for the street because it absorbs moisture quickly. Sold in metal cans. I can't afford this stuff!

Performance Friction High Performance DOT 3 has a good dry boiling point but a crummy wet boiling point. It comes in metal cans which is good for shelf life and sells for $7.87 per 16 ounce container. If you are even considering this fluid, I would go with the cheaper Ford Heavy Duty DOT 3. In either case, change this fluid frequently due to the poor wet boiling point.


Date: Mon, 22 Feb 1999 16:57:46 -0800

I got this on another list. It all makes sense to me.

More than you ever wanted to know about brake fluid.

Brake Fluid Facts
by Steve Wall

As a former materials engineering supervisor at a major automotive brake system supplier, I feel both qualified and obligated to inject some material science facts into the murky debate about DOT 5 verses DOT 3-4 brake fluids. The important technical issues governing the use of a particular specification brake fluid are as follows:

Additionally, some technical comments will be made about the new brake fluid formulations appearing on the scene.

First of all, it's important to understand the chemical nature of brake fluid. DOT 3 brake fluids are mixtures of glycols and glycol ethers. DOT 4 contains borate esters in addition to what is contained in DOT 3. These brake fluids are somewhat similar to automotive anti-freeze (ethylene glycol) and are not, as Dr. Curve implies, a petroleum fluid. DOT 5 is silicone chemistry.

Fluid Compatibility

Brake system materials must be compatible with the system fluid. Compatibility is determined by chemistry, and no amount of advertising, wishful thinking or rationalizing can change the science of chemical compatibility. Both DOT 3-4 and DOT 5 fluids are compatible with most brake system materials except in the case some silicone rubber external components such as caliper piston boots, which are attacked by silicon fluids and greases.

Water absorption and corrosion

The big bugaboo with DOT 3-4 fluids always cited by silicone fluid advocates is water absorption. DOT 3-4 glycol based fluids, just like ethylene glycol antifreezes, are readily miscible with water. Long term brake system water content tends to reach a maximum of about 3%, which is readily handled by the corrosion inhibitors in the brake fluid formulation. Since the inhibitors are gradually depleted as they do their job, glycol brake fluid, just like anti-freeze, needs to be changed periodically. Follow BMW's recommendations. DOT 5 fluids, not being water miscible, must rely on the silicone (with some corrosion inhibitors) as a barrier film to control corrosion. Water is not absorbed by silicone as in the case of DOT 3-4 fluids, and will remain as a separate globule sinking to the lowest point in the brake system, since it is more dense.

Fluid boiling point

DOT 4 glycol based fluid has a higher boiling point (446F) than DOT 3 (401F), and both fluids will exhibit a reduced boiling point as water content increases. DOT 5 in its pure state offers a higher boiling point (500F) however if water got into the system, and a big globule found its way into a caliper, the water would start to boil at 212F causing a vapor lock condition [possible brake failure -ed.]. By contrast, DOT 3 fluid with 3% water content would still exhibit a boiling point of 300F. Silicone fluids also exhibit a 3 times greater propensity to dissolve air and other gasses which can lead to a "spongy pedal" and reduced braking at high altitudes.

DOT 3 and DOT 4 fluids are mutually compatible, the major disadvantage of such a mix being a lowered boiling point. In an emergency, it'll do. Silicone fluid will not mix, but will float on top. From a lubricity standpoint, neither fluids are outstanding, though silicones will exhibit a more stable viscosity index in extreme temperatures, which is why the US Army likes silicone fluids. Since few of us ride at temperatures very much below freezing, let alone at 40 below zero, silicone's low temperature advantage won't be apparent. Neither fluids will reduce stopping distances.

With the advent of ABS systems, the limitations of existing brake fluids have been recognized and the brake fluid manufacturers have been working on formulations with enhanced properties. However, the chosen direction has not been silicone. The only major user of silicone is the US Army. It has recently asked the SAE about a procedure for converting from silicon back to DOT 3-4. If they ever decide to switch, silicone brake fluid will go the way of leaded gas.

Brake system contamination

The single most common brake system failure caused by a contaminant is swelling of the rubber components (piston seals etc.) due to the introduction of petroleum based products (motor oil, power steering fluid, mineral oil etc.) A small amount is enough to do major damage. Flushing with mineral spirits is enough to cause a complete system failure in a short time. I suspect this is what has happened when some BMW owners changed to DOT 5 (and then assumed that silicone caused the problem). Flushing with alcohol also causes problems. BMW brake systems should be flushed only with DOT 3 or 4.

If silicone is introduced into an older brake system, the silicone will latch unto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound your initial mistake and change back. Silicone is very tenacious stuff and you will never get it all out of your system. Just change the fluid regularly. For those who race using silicone fluid, I recommend that you crack the bleed screws before each racing session to insure that there is no water in the calipers.

New developments

Since DOT 4 fluids were developed, it was recognized that borate ester based fluids offered the potential for boiling points beyond the 446F requirement, thus came the Super DOT 4 fluids - some covered by the DOT 5.1 designation - which exhibit a minimum dry boiling point of 500F (same as silicone, but different chemistry).

Additionally, a new fluid type based on silicon ester chemistry (not the same as silicon) has been developed that exhibits a minimum dry boiling point of 590F. It is miscible with DOT 3-4 fluids but has yet to see commercial usage.


speed bleeder animation

From: Brad Cook (
Date: Tue, 29 Apr 1997 18:14:02 -0500 (CDT)
Subject: (rx7) [gen] RE:speedbleeders

>Sitting on top of my monitor is my new set of speed bleeders waiting to
>go in. They seem like a really neat idea and the construction looks to be
>of good quality. Only suggestion would have been a cap to cover the ends
>when not being used

I put a set on my R1 a few weeks ago, and they work really well. However, I did snap one in half inside the caliper, so be careful as to how much you tighten them. If you are anal about having air in you brake lines and bleed them often (like me) these are invaluable.

I even got great service from the developer of the product who sent me a replacement bleeder AND later on an upgraded version of the bleeder valves at no charge. Order at Speed Bleeder.


Date: Fri, 29 May 1998 15:52:03 -0700
From: "Drew" (

The front calipers are 8mm
The rear calipers are 7mm
and the clutch slave cylinder is 8mm (Make sure you get all five).

Make sure you get the "long nipple" varity, much easier to keep the bleed hose from falling off.


Date: Wed, 17 Nov 1999 01:48:18 -0800
From: Max Cooper (

I bought some Speedbleeders [] direct from the manufacturer and just wanted to pass on the sizing and ordering information. Speedbleeders are brake bleeder screws with check valves that make it very easy to bleed the brakes.

For the [3], you need two SB7100 (7mm x 1.0) and three SB8100 (8mm x 1.0) bleeders. The extra one is for the clutch slave cylinder. Russell resells them with different part numbers, but you should be able to select them using the sizing information I included here. Some auto parts stores and many mail order suppliers sell the Russell ones.

Ordering from Speedbleeder directly was cheap and easy. They knew the sizes, including the clutch bleeder, and shipped them quickly. Total cost for all five plus shipping was $34.50. The package included the bleeders, rubber caps, a sticker, a brochure, and installation notes.


Some comments have been made that painting the calipers may cause some degradation in the ability of the calipers to disipate heat. Others have said that a layer or two of paint shouldn't matter too much. I am including this here in case you decide to do it.

Personally, I have seen some people sand down the "MAZDA" letters on the calipers so they are a shinier color than the rest of the caliper, and think that looks good. Or I may paint just the surface of the letters red.


Date: Tue, 26 Aug 1997 10:47:35 -0500
From: (Chris Roberts)

>Im interested in painting my calipers. Any recommendations
>as to what type of paint and how to apply it?.

Check out Folia Tec. Their number is (888) 486-0067. E-mail is They have caliper lacquer is six different colors.


Date: Mon, 6 Oct 97 10:23:39 EDT
From: zgluszek@VNET.IBM.COM

The Sport Car Brake Caliper Lacquer manufactured by Folia Tech is being finally imported from Germany. There are 6 colors available. I remember that not so long ago a few members were looking for a source. This lacquer is being imported by:

International Trade Marketing
257 Crystola Canyon Rd.
Woodland Park, Co. 80863


Date: Fri, 25 Sep 1998 07:58:27 PDT
From: "Firas Arabo"

I have already done this on my car WITHOUT any special paint product specific to calipers. It is all in the application. I have successfully used two methods, one for the front and rear each.

On the fronts, I sandblasted the calipers, prepped them with a 3M wax remover that can be found in any paint shop. I then used two coats of basic KRYLON sandable primer (needs no more than 20 minutes between coats). I used the grey primer since I was painting them black. I followed up with three coats of Krylon Gloss Black paint, allowing atleast 12 hours drying time between coats in low humidity. I then used a scotch brite disc on an exhaust cutter type tool and touched up the "MAZDA" on the fronts. I then followed up with two coats of KRYLON clear coat. The clear coat needs no more than 5-6 hours drying time (dry to touch).

On the rears, they are not aluminum, so the procedure is a bit different. Before the primer is added, you MUST add a compound to prevent the rears from rusting throught the paint. I have finally found a base compund that actually works, and it is RUSTOLEUM Cold galvanizing compound with zinc-phosphate. One coat of this stuff is all that the rears will need for protection through atleast two years. Follow this up with the normal procedure explained above.

I also will add a coat of clear to all of the calipers about once every 10k or so just to keep the finish beautiful.

When it was all added up, I used 1 can of the primer, two cans of the gloss black, and one can each of the clearcoat and Rustoleum compound, all of which are very easy to find at your local Home Depot/Builder's Square/ whatever for around $25.

If anyone has found a better method of application or better common products I would be very interested to know what has worked for you.


Other people said they used Testor's model paint. It is supposed to take the heat very well. --Steve


Date: Mon, 30 Nov 1998 09:53:03 -0800
From: "Jim LaBreck (ECA)"

I have polished calipers... took about 25-30 minutes per side, with the right tools for the job, which is a high speed die-grinder with sanding wheels and a 4" grinder for removing the MAZDA lettering quickly. They haven't had to be polished since, and only the outside "half" of the caliper needs to be polished.

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