Originally Posted by TonyL128
Racing Brake has a group buy list for their BBK conversion using the standard 135i calipers. With their piston upgrade kit, Hawk track pads, you will get 95% or better performance of other BBK upgrade kits, at 1/3 the price! The shipping will also be cheaper to Australia. Here is the link:
A proper BBK will run cooler and cool off faster then an upgraded 135i caliper. That said, the upgraded 135 set up is more then enough for most people.