Selecting Coilover sping rates


New Member
May 18, 2005
Hello all,

I'm getting ready to install a Tubular K-member and coil overs and have a few questions. Please keep in mind this vehicle is intended to be a canyon carver, so deterioration in ride quality is not an issue. I want the car planted, period.

When selecting spring rates, is the a linear or static relationship between Front/Rear? That is to say, is the F/R relationship a percentage, or is there a formula that states "pick the front rate and subtract X" to arrive at the rear rate? Also, since this is a convertible, will the selection increase or decrease the rate based on the additional weight? The setup will include Koni yellows.

Any suggestions for spring rate combos is encouraged. Thanks in advance for the assistance.

  • Sponsors (?)

I have the UPR kit which uses QA1 coilovers, after talking with me about my intentions, they suggested the 175lb springs. If you are not concerned with ride quality and wish to remain planted like the car is on rails, I would suggest the 225lb springs or a stiffer spring if they offer it. As far as the nature of the relationship between the front and rear springs, I am curious as well. I would guess the relationship is more linear, as an absolute F/R ratio would fail to take into consideration changes to F/R weight bias and other factors. Good luck!