[Shadowfax028]

Just wondering if anyone here with experience can recommend a good Spring set suitable for auto cross on the M235i.

[Sail Boat]

Not really.

I'm sure I'll get flack for that opinion, but I had the Dinan springs on my M235i. Aesthetically they were great, but I found the suspension to be oversprung afterwards - the dampening modes seemed unsettled and I much preferred the OE coils. I did have one HPDE experience with the Dinan springs, but can't comment on how they performed; I was too focused on my instructor yelling at me to use more throttle and brake later

That being said, I think the four or five spring options we have for the M235i would be a good match for some Bilstein B8 Dampers. Of course, this will require coding out EDC but this is very cheap and easy to do. Talking about cost, the full B8 kit for the F22 is only $700, plus springs you're looking at a price tag under $1,000. Although a completely different car, I had B8's and H&R springs on my E30 and it was excellent at Summit Point HPDE.

I opted for the KW v3 kit and it has been nothing short of marvelous - I use OE top hats and the system is perfect; feels like an entirely new car. I haven't yet taken the car to the track but will this year.

TBH, I've owned many a car and springs alone never worked out - I frequently found myself upgrading the damper later on and asking why I hadn't done it sooner. Thought I would have learned by now!