For the sake of science (and those that are interested....) a few spring and shock dyno's from my OCD collection of trying things out in an effort to find a well balanced track setup that's "streetable" enough to drive the kids to school on the way to a track day at Sebring.
-April 20th, 2019 EDITED to include a cross link to my final setup using stock M3 EDC electronic shocks with DSC Sport completely configurable active suspension controller based off G force. Dyno plots for stock EDC shocks posted in this link as well with an overlay of the stock M2 shocks in the same graphs!
DSC Sport , Active System Retro-fit
https://f87.bimmerpost.com/forums/sh....php?t=1603360
Roehrig data files available for those that are interested.
Start of with springs and the next forthcoming will be dampers..
Stock:
Front 218 lb/in (linear)
Rear 331-681 with the 2.5-3.5" compressed range of 528 -681 lb/in
So the rear springs
ARE PROGRESSIVE...flashback to the E36 rear beehive days presumably...this was very interesting to find out..
Ride Frequencies 1.52 Hz Front / 1.58 Hz Rear (using 604.5, 528 - 681 averaged)
Dinan:
267/670 lb/in both linear (I should note this kit was from my F80, the Dinan M2 kit has a 750 lb/in Hyperco and helper spring setup, front is the same)
Ride Frequencies 1.69 Hz Front / 1.67 Hz Rear
BMW M Performance Suspension (KW V3 ish..):
233 / 640 lb/in both linear (consistent with TUV approval in manual) which is a bit of a surprise as KW, who makes BMW MPS uses progressive up front at time.
Ride Frequencies 1.58 Hz Front / 1.63 Hz Rear
JRZ RS TWO:
Came with 450/685 lb/in Eibach ERS 2.25 springs and helpers,
Ride Frequencies 2.19 Hz Front / 1.69 Hz Rear (pitch, no "flat ride")
Spring MR for above ride frequencies 0.956 / 0.58 front and rear