Why the high spring rates?

I am not sure that I can give a great answer for that. I do know that the pro teams that run these cars and similiar cars (Integra GSR, 99 Civic Si) all run close to the same spring rate.

So instead of testing all the different spring rates possible I started with something close to what the pro cars were running then depending on the track, tires, etc I will make adjustments up or down in spring rates.

If you want to know why the Integra uses 700-1300 lbs springs and why the RX7 uses 250-350 lbs springs it has to do with the motion ratio, effective sring rate, suspension design, etc and things that you need to calculate.

Also when I was co-driving a ITA CRX we did some real good testing on spring rates and generally the higher the spring rate the faster the lap times, until a certain point when the car starts to bounce, skip through the turns, which will result in a car that is hard to drive and harsh over the bumps.

Scott Seck
#38 ITS GSR