nitrous87

My third gen project is starting to come together and I decided today that it might be a good idea to invest in some rear coil spring. I have the car set up for drag racing, it has 4.10 gears with a fourth gen rear diff. I managed to squeeze 29/12/15 inch hoosiers under it by cutting the bump stops. It should be putting down about 500hp to the flywheel. What would be a good set of rear springs that would give me good launches without squatting and eating my rear tires.

AlkyIROC

The springs only need to be strong enough to hold the car up at ride height. The shocks are what do all the work. The suspension has to move so if a spring is too stiff, the shocks can't do their job. If the spring is too weak, the car squishes the springs too much and the back end sags.

I ran V6 springs for many years before installing coil overs. You can find different spring rate springs by measuring the thickness of the spring wire in the factory springs. Smaller diameter means a smaller spring rate but may also be too soft for the weight. It all depends how heavy the back of the car is.

nitrous87

I also decided to run v6 rear springs to get more ride height. I was just worried that they might be to soft and rub the slicks on launch. The car is completely gutted so it is very light in the back. So a pair of summit or Lakewood rear drag shocks would probably be a better investment then.

Kat

iTrader: (4)

:shrug: I'm running cut NNL springs from a 89 IROC and Koni red's set on the middle position. Rides great on the street and does well at the track.

articwhiteZ

iTrader: (56)

shocks 90/10s front

50/50 rear. with stock springs in the rear

with stock spings in the front my 60 foot time avg 1.54

but thats with my old 383. lot better now

cycleguy04

Would you please elaborate what 90/10 and 50/50 mean? Thanks.

keeslinger31

I believe its the valving in the 90/10 strut will allow the front to lift faster and come down slower, also the adjustable shocks you can just dial in to what you want

articwhiteZ

iTrader: (56)

now going with front coil overs (90/10)
and also rear coil overs & double adjustable shocks.

AlkyIROC

I use SPA1 adjustable struts on the front. If I want to go out and play during non competition, I turn them to full loose so the front pops up quickly. During competition I crank them up tight making it hard to lift the front and I can still pull the wheels off the ground. Travel limiter cables will be shortened to keep the wheels from fully extending which makes it even harder to lift the front.

Rears have 12 way double adjustable coilovers. That way you can fine tune the extension and compression for different track conditions.

With a slower car, making the front end light and using shocks to allow quick front end extension will help transfer weight to the back. The faster you go, it becomes a problem to keep the front end down.