No track car is complete without a proper suspension system. The M2 (F87) comes with a great street focused suspension that is comfortable on the track. Many of the components come directly from the M4/M3, and if the car is only going to see light track use the stock setup is likely good enough. After spending a couple days with the car on the track I decided I wanted a more track/race specific suspension system. The main things I wanted to change over the stock setup is that I wanted to put in more negative camber, I wanted a lower and tighter ride, and I wanted adjustability to accommodate different tracks and different setups.
To accomplish this I choose KW Suspensions 3 Way Clubsport coilover kit and their adjustable camber plates. I also upgraded the rear camber arm bearing with Bimmerworld's M4 kit and the front upper control arm bearing with Bimmerworld's M4 kit. This will take out some of the snappiness when quickly unloading the suspension. I decided to keep the sway bars and control arms all stock for now, but after we get some more track testing done we will decide if any further medications are needed.
Like the suspension, the M2 stock brakes are good for street and light track duty but not up for the task of heavy track use. I had already upgraded the pads and fluid but found the brakes still needed more stopping power. Instead of going with Brembo or StopTech or AP I decided to go with Sparta Evolution out of Washington. They have fantastic track and race kits at a reasonable price that should be considered before simply going with the bigger brands.
Their calipers are forged in aluminum, come powder coated or anodized, have quick release pad retainer pins, and there are a ton of pad options to choose from. For the M2 we were able to upgrade to Sparta Triton 6 piston in the front and 4 in the back (stock is 4 and 2). I went with their 3.0 pads which are designed for heavy track use but manageable for the street. They have less and more extreme pad options as well. For rotors I went with Sparta's Pegasus two piece floating hat rotors with an S-slot pattern. They are 380mm front and back (just a bit bigger than stock). This should be a huge improvement over the stock setup. There is a chance we will still need some brake air ducts which we can fabricate if needed.
Edge Motorworks of Mountain View helped me select the suspension and brake systems as well as doing all the install and adjustments. Edge also did a corner balance and track focused alignment. We did find we needed a 5mm spacer (3mm might be enough) in the front to properly clear the wheels. Now its time to test it out on the track and fine tune the setup to optimize the performance.