Originally Posted by BiscottiGelato
I thought the idea is to keep the supposingly reasonably competent 135i 6 pot calipers but solve the heat problem with upgraded rotors?
The 135 calipers aren't very competent...they don't dissipate heat very fast at all and don't seem to apply even pressure. The pressure issue is most likely due to the fact you cannot bleed both sides of the piston banks. Some air gets trapped in there.