Christa writes about stock '7s...
Date: Tue, 22 Jun 1999 10:51:53 -0400
From: Christa Meck (cmeck@frontiernet.net)
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)...
Weights:
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):
65
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.
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Date: Wed, 20 Jun 2001 12:38:10 -0400
From: "Wilson, Mike" (MWilson@unispherenetworks.com)
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.
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From: Shiv S. Pathak (Shivp@worldnet.att.net)
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 (front) 817 699 772 757 (rear)
---------------------------
2) With BMK (Genesis)
Total: 3024 F/R: 0.493/0.507 L/R: 0.519/0.481 (front) 800 691 769 764 (rear)
----------------------------
3) With Odessey battery relocation
Total: 3034 F/R: 0.486/0.514 L/R: 0.516/0.484 (front) 788 687 778 781 (rear)
*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.
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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.
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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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