cornerweighing my FD - a work in progress
 

The new coilovers are in and I took car for a spin today and they felt insanely great. I can't believe 900 lbs springs can feel so good. Not jarring at all. The car needs an alignment but it still felt good enough to drive around. No pulling or shaking.

So I put her on the corner scales tonight to check the starting points.
Notes:
-ride height is off as you'll see, mostly in the right rear. That is because I just bolted them in from the car I got them from.
-sway bars need to be disconnected before doing any adjusting. So these numbers are skewed slightly.

Results:
http://209.177.55.37//images/rx7/cornerweights.jpg

I will use this page as what steps to follow on how to adjust (I posted 2 links in other thread but they are good): Understanding Corner Weights - How To - Hot Rod Magazine

This one looks good too:
Grassroots Motorsports » Understanding Corner Weights

I'll update this week with how I adjust and how it changes the weights.

I have also recently corner weighted my track FD, I dont have my sheet with me for exact measurements but with myself and 1/2 tank of gas it weighted in at 1278 kgs with a perfect 50/50 distribution and 320,5kgs on each wheel.

Where'dya get those savory JRZ's?

please do update this thread.

also, which scales are you using?

congrats!

i believe it. get quality shocks and you'll have a quality ride, even with stiff ass springs

are you doing this yourself or at a shop? i've been looking for a local shop in jersey that does corner weighing

Oh yeah, FYI, you probably don't really need those helper springs, the car will never see full droop condition on the road... I had the same question when I first put the GC's on.

anzpoopy - i'm doing it myself. i borrowed a friends long acre scales. i have heard Will DiGiovani from Precision Motorsports is very good at this (908 832 - 6572). also TTP in northern NJ has started corner weighing too. www.ttperformance.net

http://72.14.209.104/search?q=cache:...lnk&cd=5&gl=us

thanks ptrhahn :)

Where did you get those coilovers? And how much were they?

i got em used. but you can get em new:
http://www.jrzusa.net/products/

although an FD application isn't listed on the price list, they do make them special order:
http://www.jrzusa.net/prices/jrz_prices.pdf

First Adjustment: I was told motion ratio was .6, so I took a guess on how many turns to lower the rear coilovers. There are about 10-12 rotations per inch. I took a guess to lower the Left Rear 5 turns and the Right Rear 6 turns, and it turned out perfect. Ride height at every corner is now 25.25 inches. Rear sway bar is disconnected but front is still connected. Still 1/4 tank of gas and I will put more in tomorrow night. That will improve the distributions I believe.

http://209.177.55.37/images/rx7/cornerweights2.jpg

The main improvement is that the Cross weights ((RF + LF)/ttl weight) went from 47.8% to 50.2%:coolugh: As per those articles I listed, this is hugely important to be as close to 50% as possible. Mission accomplished.
Tomorrow I hope to do one more measurement by adding more fuel so its a real world weight, and by disconnecting front sway bar (in case there is preload).

I put all the measurements in a spreadsheet here:
www.ponycars.net/cornerweights.htm

I almost got killed because as I was jacking up the rear (fronts already on the scales), the front wheels were being pulled back and fell off the scales and the car rolled back and pinned my shoulders and head against my garage door. I wiggled out. Luckily the door is weak aluminum and dented in easily :)

You're probably having the same problem in the rear that I had with my JRZ's in that the lower shock bolt is too short. I'd recommend the following solution before you loose it at a bad time.

https://www.rx7club.com/suspension-wheels-tires-brakes-20/custom-fd-rear-sway-bar-end-links-how-695989/

Alan

be careful man.

you should really throw some kind of ballast in the driver's spot to simulate your own weight.

edit: nevermind i see it says with driver. i'm seriously having a problem with glossing the reading. i blame school.

done finally.
added 9 gallons of fuel (gained 58 lbs).
no driver, all swaybars disconnected, 2825 lbs, 49.9% front, 50.1 rear.
With driver, 3033 lbs, 49.2% front, 50.8 rear.
did it on garage cement slab floor. i think its pretty flat. i'll check on another spot but for now, its good enough. rearward weight bias :)

ponycars.net

the yellow highlights are when i took the measurements front headed in versus backed in. since floor isn't flat. i took the averages and with me in, front is 49.45% and rear is 50.55%.

holy crap man that must have been not fun.
at least throw a tool on the scales to act as a wheel-chock the next time you do any stuff like that, wow.

gives me the shivers.

nice final results though, awesome, you have to be totally stoked on those coilovers, such a nice product.

nice good thread im planning to do the same this next year!

I PM'd 2MCHPWR my cornerweights but I also thought it might be helpful to post here as well for others. This data is for a single turbo '93 with 3/4 tank of gas, me (180#) in the driver's seat, and a Kirk roll bar as the only weight-adding mod. Sway-bars disconnected. Sorry it's not in the cool spread-sheet form but you get the idea.

Weights in pounds

LF = 739 RF = 673
LR = 830 RR = 763

LF + RR cross = 1502 (49.9%)
RF + LR cross = 1503 (50.1%)

L = 51%
R = 49%
F = 47%
R = 53%

Total weight = 3006

F = 5 caster, -1.8 camber, 3 mm toe in
R = -2.0 camber, 5 mm toe in