IMO, you can spend lots more money, but the best setup is Koni Sport Shocks (yellow adj) and the stock springs. I've had new set of H&R springs on hand for months and finally pulled it down to install them this weekend. After a direct comparison of OEM and H&R, the OEM springs are larger wire by almost a full mm with the same # of coils/diameter. This would explain why some folks report the H&Rs are way too stiff/low. The car is riding on the bumps stops because the H&R springs aren't stiff enough for the lower ride height.
So...., I decided to keep the OEM springs on and I cut one coil from the bottom of the front springs and one coil from the top of the rear springs. Also cut one level of the front and rear bumps stops to account for the lower ride height. The car is essentially perfect for street/track, IF you have the alignment set to maximize grip....
Forzda, what do you think about using the RPM Sport springs with Koni Yellows?
