Sean: What is the difference in these A8 rotors? I am running A8 rotors on my Bira System 1 and I think they are 314 x 25 (i.e. 25 mm not 30 mm thick) You said: "993tt caliper, RS2 bracket, A8 323x30 rotor or 993tt caliper, ECS bracket, A8 314x30 rotor (aka ECS stage 2)" Dave F.