Upgrading M-Sport Suspension Options

[rock0012987]

I recently bought a 2011 135i e82 M-Sport and I'm looking to upgrade the suspension. I'd like a sporty street setup (won't track the car as I have no track near me) and yet with some compliance to handle the often bumpy city streets. The car has aftermarket bushings, but no M3 control arms. I'd prefer not to spend more than around $1500 for a coilover set. I can't lower the car much at all given my driveway has a steep downward transition coming off the street, and I'm currently lightly scraping the bottom of my car going over it. I've looked at the Bilstein B12 Pro Kit, Bilstein B14 PSS9 coilover kit, and the ST XTA coilover kit. I'm leaning toward the ST's given they have rebound adjustment and camber plates included (will want ~2 degrees of negative camber). However, I emailed ST given I'm concerned about the minimum lowering on the ST XTA's 1.4" (~35mm) would make my car too low and scrape on my driveway transition. The ST rep said their 35mm min lowering is assuming the base (not M-sport) suspension. I've heard the M-sport suspension is around 15mm lower than the base suspension. If that is all true, I think I could get away with the approx 20mm lowering.

Anyway, I'm new to all this suspension stuff, and would really appreciate any thoughts on the two Bilstein options and ST XTA option. Also, if any of you installed any of these options as a upgrade to your M-Sport suspension, I'd very much like to hear about what kind of lowering you saw, and also how you think your upgraded suspension performs.

[mkeiser]

IMO for sporty street with good compliance I would go with Koni SA shocks/struts. keep your m sport springs if you're ok with current ride height. h&r or eibach springs if you want to go a little lower. dinan fixed camber plates if you want some camber.

[jwolf]

If you don't need to go lower. Keep the springs you have and go Koni Sport. They are adjustable and pretty amazing. Fixed camber plates (Dinan or Turner) can get you the negative camber the car really needs. The M3 control arms get you another -.5 I think. Good tires are a must. I run a square tire setup and often wonder if it would work if I went lower. So happy to keep the stock height.