best spring rates

I'm testing it out in the next few months. I put 560# spring in the front right now. Stiffer and the shock seem to handle ok. The real test is when I hit the track hopefully sooner than later. I just need to find the time. The next track for me is Black Friday but I might have to bring the M3 to test tire for Bridgestone.

In the end it really depends what your goal is. Making it track car only, weekend warrior, or occasional track toy car. The more you shift it toward track car the more the street will suffer it is all bout compromise.

 

Scuderia
Front 437
Rear 620

F430
323
596

Just a bit background. This is me.
Andrie Hartanto | BimmerWorld Racing

I have not changed the rear spring. The goal for me is to achieve a good balance while using stock shock. So I'm going up the spring rate slowly. Based on my experience and if my car is a complete track car I suspect I will want front spring rate around 800-1200. Rear around 800-1000. However, I suspect I will need to revalve the shock or just replace it with Penske. The motion ration for the car is .7 front and rear based on rough measurement.

 

The stock rates are progressive, and have been posted before, but details also listed in the service manuals.

I have 504 front/615 rear lb/in on my 360 with stock shocks, working fine. I had a 670ish spring in the rear and eased it back. I used the Swift Z65-152 Spring size(6"/2.52ID), but needed spacers for length, so a longer spring makes things simpler.