85 GSL-SE Track Suspension/Alignment help needed
 

So I'm building a dedicated track rat out of my old RX-7 GSL-SE. I'm hoping some of you 1st gen rx-7 gurus/racers have some advice on alignment specs and ride height (the coilovers on the front are easy, might have to cut a coil to adjust height out back)

Suspensionwise, this is what it has:

Ground Control camber plates (front)

Ground Control coilovers (front)

tokico illumina 5 way adjustable struts all around

Eibach springs all around

Suspension Techniques front swaybar

removed rear swaybar.

I think this is fairly close to what the spec7, PRO7 spec suspensions were although my spring rates are not as high. not positive tho.

The car is basically for track days & HPDE so full race specs are great.

Very interested in the conventional wisdom on the proper ride height nad how to achieve it.

any help/tips appreciated.

thanks.

I used to run a class in Canada that was similar to Spec7, but we used street ported 12A's
I ran:
400 inch/lbs springs up front
175 inch/lbs springs out back with one coil cut
Ride height was as low as we could get the car without bottoming it out on the track. If I recall correctly we had the car about 4.5" off the ground at the front frame rails. The rear was pretty close.
The ride height is really going to depend on what wheels / tires you run.
I ran about 3.5 degrees of negative camber up front with 205/60/13 Toyo RA-1's on stock rims (series rules)
I think with a wider rim the tire carcass would deflect less, so you could step down on the camber

Best thing to do with the car is start looking at the g-force tri-link rear suspension kit.
If you want to stay reasonably stock, go through the watts link and ensure it allows smooth movement of the rear axle. Next, put new bushings in the entire front end and the lower rear suspension arms (leave the top arms alone as you need the compliance as the rear end moves)

-Trent

great tips. thx

I've managed to get my car to the point that it handles great, but I haven't taken any measurements on it. I use the same settings for daily driving and racing.

I also use lighter springs (275/150) but compensate with heavier swaybars (Respeed front/adjustable rear). That gives me the performance to race, but not so stiff that I can't daily drive it, which is very important to me. Almost zero body roll, and a very nice stable setup. :)

With a heavier than stock front swaybar, you might be happier putting the rear bar back on. I tried it both ways when I had the stock front bar, but after upgrading that I found the car could finally make good use of the rear bar. I run my adjustable rear bar on the stiffest of the three settings.

I've had a trilink setup sitting on a shelf in my garage for a couple of years now, but the car handles so well as it is that I doubt I'll ever get around to installing it.

You can get adjustable perches for the rear (basically the same function as a coilover) from www.re-speed.com That saves you from having to cut coils on the springs, and you can set the ride height exactly where you want it. Spring rates are also up to you, many choices available.

If you want to get an idea of what ride height I'm running at, you can check out some of the videos in my signature line.

Good luck with your build. Feel free to let me know if you have any questions. :)


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