[wannafbody]

How do you know what the perfect spring rate is for a car? How do you know if the car is under or over springed?

[00 Trans Ram]

Be prepared to change the rates. Here's just a very small example.

Take 3 cars we have on course. A softly-sprung LT1 Camaro, a stifly sprung BMW and my car (in between). In some twisty-but-smooth turns, the BMW is fastest, me second, with the LT1 behind.

However, when we are about to come onto the back straight, there are some bumps right at the beginning coming out of the turn. The BMW jumps over them, delaying his ability to get on the gas. The LT1 is able to lay into it and run away from people. I'm in between.

So, it depends where you want to be fast, also. Ideally, it's easier to pass people on straights. But, if you go too slow in the turns, you're gonna get passed (and probably spin out because the car isn't handling well). Plus, we're road racing - we like turning!

[mitchntx]

Be prepared to change the rates.

Spring rate really is a moving target. The best you can hope for is to get it close and then use tire pressures and wheel spacers to adjust the effective rate in a range.

I've gone from 900 to 800 to 700 to 650 and back to 750 over the last few seasons.

That's why it's a great idea to keep meticulous notes and record as much data as you can.