Originally Posted by dex37
Unsprung weight should also be lower. I still wonder why they put such huge disk at the back of the GTS. As far as I know, the E9x M3 has only problems with the front brakes. Sport brake pads are usually enough.
For such a low production volume, pet-project car, it's all about breaking even financially (or lose as little as possible). Therefore they used off-the-shelf Brembo calipers which were designed to work on rotors of specific sizes.