E36 M3 spring rates

[SteveTVM3]

I'm looking at a set of ACS type I but I need some stiffer spring rates in the rear to accommodate the 10" rears. The coilovers are KW V3 and I'm wondering if a 600lb spring in the rear will be enough?

[NegativeCamber]

id say you are close to if not, at the valving limitation of those kw shocks. so with a 600lb spring it may be stiff enough for your application, but under-damped, thus being counterproductive in trying to achieve stiffening up the rear.
you also have to take into consideration how much your fenders are rolled and how low you plan to be.

[SteveTVM3]

I just called KW and unfortunately they don't offer a linear spring conversion but do have the clubsport rear spring which are 20% stiffer than the street setup. I'm not entirely convinced that this will allow me to run the 10" rears.

[NegativeCamber]

just figure out the inside diameter of the spring on there now and get the appropriate linear spring. hyerco makes 2.25" and 60mm springs. either one of those should fit on the perch. the only thing you need to ask KW is the maximum spring rate you could run on those shocks.

[SteveTVM3]

KW says 61mm. As for max spring rate on the shocks, they put that question through to the motherland. Germany will call me with the answer sometime this week.

[Yarberrymt]

Just had a nightmare finding shorter rear springs.

But I'll be going with ~900lb rear for tight fitment.

My probem was finding shorter springs. NOBODY makes a 5" 2.5"ID spring..

[Eric M]

5 inch springs are hard they need to be custom, you can buy 4 inch springs from swift or hyper I think.