Last updated: April 27, 2003

Corner Balancing

Christa writes about stock '7s...

Date: Tue, 22 Jun 1999 10:51:53 -0400
From: Christa Meck (

My car: 1993 RX-7 Touring with Bose Acoustic Wave System, sunroof, leather, cruise. You name it, it's in there.

Comparo car: Andy B's 1995 RX-7 R2. Extra oil cooler and R goodies.

Corner weights were taken _without_ driver. Both cars started the day with a full tank of gas, but I imagine Andy's was down more than mine because he had 2 drivers run before weighing, and I only had 1. Gas tank is more to the left than the right.

From the scales at Devens (Ayer Tour)...


      My Car                               ABs Car
    Total: 2878                          Total:  2813
LF:  729      RF:  719              LF:  700        RF:  709
LR:  746      RR:  680              LR:  730        RR:  676

Ed.'s note: I calculated the percentages based on Christa's numbers:

      My Car                               ABs Car
    Total: 2878                          Total:  2813
LF:  25.33%   RF:  24.98%           LF:  24.88%     RF:  25.20%
LR:  25.92%   RR:  23.63%           LR:  25.95%     RR:  24.03%

We know that the RR is the difference between the "normal" straight pipe and the Borla. (Borla go good.) We figure that the LR difference is some stuff for the Bose. I believe the wiring comes up on the left. After that, it's your guess.

Differences (lbs):

29        10
16         4


From: C.E. Howell
Date: April 26, 1999

I used the FWS method (friend with scales ;) about 1/2 tank, me in seat (about 160 lb), car on scales, friend reads/calculates, I get out, jack car and adjust, get back in, lather, rinse, repeat. Seven cycles of adjustment and I ended up with:

	LF:  800	RF:  740

	LR:  808	RR:  736  

Ed.'s note: I calculated the percentages based on C.E.'s numbers:

          Total: 3084
	LF:  25.94%	 RF:  23.99%

	LR:  26.20%  RR:  23.86%  

Some of it may be luck, some may be inaccuracy. Was never sure the suspension was settling appropriately each time jacking up and letting down. A few times the results didn't really make sense with the adjustment, but ultimately things went in the expected direction. I haven't gone back to measure ride heights. I'm fighting the urge to lower my RF & RR to get better side to side balance, but it's time consuming and the old "enemy of good is better" may be at work here. I've got a PCA driver's school coming up this weekend, though, so we'll see if it works.


Date: Wed, 20 Jun 2001 12:38:10 -0400
From: "Wilson, Mike" (

I was asked so here they are, with 165 lb driver, seat all the way back:

          Left         Right
front     776 lbs      714 lbs       50.2%

rear      781 lbs      703 lbs       49.8%
          52.3%        47.6%

I did not write down the weights without driver. This operation was merely a side effect of doing an alignment; my crossweight scale platform is my level surface for alignment.


From: Shiv S. Pathak (
Sent: Friday, December 03, 1999 2:19 PM

...As for exact weight distrib. benefits of a relocated battery, check it out... excuse me if the number so add up exactly, I rounded the numbers to save some work.

**ALL Weight Distribution With Driver**

1) Baseline (stock battery)

 Total:  3045
 F/R:  0.497/0.502
 L/R:  0.521/0.478

 817 699
 772 757


2) With BMK (Genesis)

 Total:  3024
 F/R:  0.493/0.507
 L/R:  0.519/0.481

 800 691
 769 764


3) With Odessey battery relocation

 Total:  3034
 F/R:  0.486/0.514
 L/R:  0.516/0.484

 788 687
 778 781

*Cross weight, F/R, and R/L distr. don't really show where the weight is. deally, you want it low and to the center of the car.


From: Steve Cirian
Date: April 26, 1999

My car was done w/ a quarter tank of gas and 220 lbs in the driver's seat. Penske coil-overs w/ Eibach springs. For more details, go to Scuderia Ciriani --> The Car.

I did not get the corner weights in pounds from the shop that did mine. He gave me the percentages. It has quite a bit off from what I expected - something like:

	LF:  29%	RF:  28%

	LR:  22%	RR:  21%

I forgot to check the sheet I got from the shop when I was home this weekend, but these should be pretty close. Traveling all the time for business sucks.

If we assume that my car weighs 2600 lbs, plus 220 for me, I get:

	LF:  818	RF:  790

	LR:  620	RR:  592

This isn't as balanced as I expected, but the shop that did it said it was the most balanced street car (i.e.- not open wheel race car) they had ever seen. Maybe I need to go on a diet - that would drop the weight in the driver's seat and even things out.

I think this is not accurate - maybe the shop that did it (Havoc Motorsport in Chicago) forgot to write down what the weights were, and guessed at it after the fact.


From: Bob TMS Murray
Date: April 27, 1999

I would have to say that I think the shop that did it for you was full of it. I've seen your site - I have a pretty good idea of what your car has in it, and I will vouch for those weights being pretty grossly off. I don't have other info to share at the moment (500miles away!), but encourage you to get it rescaled somewhere else - the figures you were given simply cannot be accurate.


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