Coilover spring rate?
Turbo Mini Forums

I'm getting the SD1 corner weighted to figure out the approx mass end-to-end, but how does that correlate to what spring poundage to use? Is there a "wet finger in the air" guesstimate / formula for this?

Without usage, suspension travel and I'm sure many other factors...how would you even guess ?

Well..I know I did when building mine....sort of.

I got one of those wee valve spring pressure tools, and jacked each wheel up via the spring/coilover mount til it just barely lifted off the ground.

I guess a little like corner weighting, albeit measuring at the actual spring mount so there is no leverage applied

So that at least gave me a starting point for a static compressed spring loading as installed in the car.

jack car up and see how much droop/free travel there is at the spring...ie fully open and then I took it from there.

At the front I ended up with 1100lb 6" springs with another 450lb 2" small one to take up the slack when fully open.

At rear I've tried a few around the 200-250lb range I think they are, but these are 11" I think.

Front is a wishbone arrangement, rear live axle. Both F/R, coilover would be a little inboard from the wheel

But as to whether stiffer or harder springs might make the car perform or handle different...surely that's always going to be down to testing on the road or track.....lots of testing.

What are any companies offering in terms of spring rates for kits you just buy ?

When i was buying my springs, I spoke to the guys at Faulkners and they actually explained how they work, how springs combined can work ( ie helper and main spring ) and actually tested various springs on their rig whilst I was on the phone saying how they'd react at various compressed heights etc
Maybe they'd be worth a call assuming you've coilovers ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will