[tjswarbrick]

Originally Posted by Matticus91

Nice, I've tried finding information on spring rates for all of the different springs but it seems to be very inconsistent. No one knows for sure.

I've seen that, and did a ton of homework on it over the summer.
Didn't document all my sources, but tried to make sure at least 2 aligned before calling the value "good." If I found a source but could not corroborate it, I left those red.

Don't take it as gospel, but it should give you an idea of what to look at.
What I had more trouble getting was amount of lowering since it varies with car and configuration.

Spring Front / Rear rate (lbs/in)
135i(M-Sport) 120 / 350
E90 Sport 145 / 460
E90 BMWP 195 / 505
E90 M3 160 / 550
Dinan E82 144 / 490
Cobb E82 142 / 457
Swift E82 201 / 503
BMWP T1/T2 135 / 420
BMWP T2/T3 146 / 460
BMWP T3/T4 160 / 495
KW Street Comfort 286 / 572

Hard since nobody will talk to me about what configuration "belongs" on my LCI 135i E88.

P/N's appear to be 31336788891, 8892, & 8893 T1-T3 Front, and
33536788898, 8899 & 8900 T2 - T4 Rear.
Certainly do your own research if you're spending your money.