I'm considering a 2006 M Coupe as a weekend and track car. I'm an instructor for BMW CCA, PCA, and various other organizations, but the only cars I've tracked have been Mazdas - a Spec Miata I race in SCCA and NASA, and a 3rd gen RX7 that was a street legal track car. I've sold the RX7 and am now looking for something to take its place. I've driven the M Coupe on a test drive on public streets, and have instructed a student in one, as well. It has some nice torque down low and responsive steering, though the suspension feels a little soft, even in "Sport" mode. Are there any specific issues with this car for serious track use? Other than a roll bar, harnesses, and brake pads, any other upgrades I'll need, such as brake ducting, stiffer front roll bar, lowering springs, etc? Any comments on handling in stock configuration? When you turn the DSC off, is it really off? All comments welcome. Thanks.
I recall hearing comments that they can be twitchy at their handling limits; since you're obviously experienced, you'd have to decide how comfortable you are in dealing with whatever degree of twitchiness may be there. However, I would tend to think it could be modified appropriately to minimize negative handling traits. I think TC Kline has tuned the Z cars extensively, for one - http://www.tcklineracing.com/index.htm. Ideal thing would be to drive one at speed on track and see how it feels to you. If you're much over 6' tall, you might not necessarily expect to fit in it w/ a helmet on. Stainless steel brake lines are always helpful for track duty, but not an absolute must. Come to think of it, TC would be a good person to field your questions, you might want to give him a call.
You could also ask Motorsport Technology Group. There is a lovely picture of one rolled smashed Z4 coupe in the Roundel but I haven't gotten around to reading the text to see why it got stuffed.
The e86 ///M tracks fantastically, even in stock form. I'd only suggest changing a few basic things (which will not impact every day drivability): Aggressive Alignment (maximize the negative camber on the front by pulling the camber pins) Better Brake Fluid (alternate ATE Super Blue and Gold for ease of flushing) Better Brake Pads (AXXIS Ults all the way around or Ferrodo 2500s up front and AXXIS rear) When I first tracked my car, it was copletely stock in every way and it was pretty darn great, as I was one of the fastest cars in the HPDE. The next time, I performed the items above (and put on different wheels, mainly to protect the OEMs from damage...they just happened to have R-Comp rubber on them) and was running at a P-car HPDE up through blue-solo and had no problems keeping up with the GT3s around the track. I will admit, though, my local track is fairly tight and, therefore somewhat easy on the brakes as you never get up a lot of speed. If you're running a harder track, I would definitely suggest feeling out the stock brakes before you go balls to the wall.
