^Played it safe and went with sizes my track buddies were running at the time.
lulz, early last year, I swore that I would just track with ZCP wheels. But, right now, I have 3 sets of wheels and may be purchasing a 4th set soon, lol.
2013 E92 M3 Jerez Black DCT ZCP
2011 E90 M3 Jerez Black DCT ZCP (Gone - traded in)
2008 E90 M3 Jerez Black 6MT (Gone - End of Lease)