Originally Posted by r53s65e90
Basically what was needed in order to develop the kit was to determine whether a completely new caliper was needed or if an existing caliper could be adapted to work with the M3.
The link you provided had not been around at all prior to the last month or so since there was no Racing Brake kit made for the E9X M3 until now. We used one of our cars for all the computer measuring for the calipers, rotors and hardware. Racing Brake saw our unique spot in the market and approached me about coming up with a game plan for the E9X community. None of the local BMW parts sellers wanted to get involved so that's when he found me and BPMsport.
In regards to the technical nature of the pistons, etc. I will see what information RB wants to publish and get back.