Very interesting thread. Here is my information and I have a question as to why you all are running a higher spring rate out back?
(1) 2007 Z4MC, S54
(2) KW Clubsports
(3) Stock KWC springs- 400lbs front and progressive rear
(4) Street (weekends and occasional wkdy) & track
(5) DEs - 10-16 days a year (8-12 events)
(6) Stock sways
(7) PS2 tires (31psi front/30psi rear- cold)
(8) No camber plates; using Turner washer kit to get around -2.3° front; -1.8° rear.
(9) Happy with the setup so far- comfy enough on the street and great on track. Want to reduce roll some more and increase mechanical grip so plan to go for 450lb front and ?? rear this winter for next year.