Johnny Import

So after scouring the web I have found the following info:
Race setup front stock location 1100-1300
Coil over. 650-750
Spirited street stock location. 700-900
Coil over. 300-400
Rear anything from 180-225

Sway bar front 34 rear 19-21

I am building a 1989 RS T-top, the build will include LS3,T56. Spohn tubular k-member with coil overs, and of course the usual sub frame connectors, trailing arms etc. Planning on using a 8 point cage. Any advice or help appreciated car will see some track and Autocross as well as street use. Are these spring rates a good starting place?

Johnny Import

Nobody can tell me if I am close! No advice?

Beater79TA

We run Ground Control Weight Jacks on the GTA with 950 fronts and 225 rears and run it hard on autocross and road courses. You will feel every bump in the road with the stiffer springs but it was worth it for the improved handling on course.

Jaysz28

iTrader: (30)

It would be helpful if you told us what you intend do to with the car.

Drag strip?

Track car?

HPDE?

Autocross?

They each have their own requirements

Johnny Import

Aggressive Street use mostly although Autocross and 3-4 track events per year.
I am used to a little rough as my name implies my background is imports, mostly Honda on coil overs.


I am prepared to live with a little harsh on the street, and prefer track manners, will live with whatever I get at Autocross!

Johnny Import

I did!

Lonnie P

Your 700-900 on the front is pretty close.


You can run more spring rate, but keep in mind things can get a little ugly on rough streets with stiff suspension... once you get too stiff you can actually lose traction as it skips across the bumps in the road. The street is far from a smooth track. The 1100 may be a little much.


The rear is totally subjective as the panhard bar height & rear bar has a great effect on balancing the car, as well as your driving style & preferences. Anywhere from 150 & up will work.


I have 800/150 with 36/24 bars & it has good manners.
It honestly does ride rougher than my friends 3500HD dump truck though.


Personally I plan to go up on the rear rate & lower the roll center to experiment next.


The 950/225 sounds interesting to me, but I'm sure it is a little rough on anything but smooth roads.

Johnny Import

Excellent feedback exactly what I was looking for. Thank you

I figured 1100 and up would be track only!

Lonnie P

I chose to stay away from coil overs for the max avail tire clearance & always figured it was safer to adjust & tweak things as I progressed. Other than easy height adjustment & a slight weight savings, I saw little benefit to coil overs.


Not sure what your experience is with this car, but by working your way up as you gain experience with the car helps you learn its limits with less risk.


As you push the car harder you start to feel the increased body roll & learn the car at its limits. Then you work into the next level of mods by going up in tire size, bars, springs etc.


The risk of starting too stiff is it feels great until it suddenly comes loose & things get ugly real fast. I'm actually glad I could push my car until it came loose at 50mph, then 60, then 70 in the same turn as I developed the car. That extra 20mph uses up a lot more road trying to save it & knowing how to be part of the car comes in handy. It's hard to un-wreck a car...


Not sure I can say much about tubular front suspension in this application. I opted for durability instead of the weight savings. The only good option would be if they modified the lower control arm angle with the aftermarket k-member. These cars get the control arms near level or inverted at lowered heights, dropping the roll center in the ground & hurting the camber curve in the process. Check this info closely before buying your aftermarket parts. I chose extended ball joints & stock front lowers to help the geometry.

plum92_camaro

You're speaking my language although on the streets I just cruise. Check out my set up in my vB garage. It is very stiff and handles outstanding. It's not finished but it's coming along nicely.

I started with 850# fronts, they weren't enough. I was nervous about going to 1000# fronts. I thought it might be too harsh to tolerate but it's not. The car follows the ups and downs in the road, actually feels smooth. Bumps that would be harsh with stock suspension are just harsher.

Johnny Import

Plumb92_camaro your build is very close to what I have written down to complete on my car thankfully at least my car is blue so won't be exactly the same! Lol

cosmick

My '94, which is the same rear suspension, is now on 300 lb / in rears, and I wouldn't call them harsh, for daily commuting, didn't cause oversteer or any noticeable difference on my favorite corkscrew ramp, from I-215 S to I-80 E, most cars take it at 40, 45 max, I took it at 60 stock and after the rear spring change. It is too firm for my mother-in-law, but not my wife or my teens.