Originally Posted by JARblue

Be careful with the Z1 2-piece rotors. I know a few people who regretted their purchase when the rotors didn't stand up to their track abuse. Brake rotors act as a heat sink for cooling so more mass is not necessarily a bad thing. The unsprung weight reduction of the Z1 2-piece is really nice but the downside they run much hotter under extreme conditions.

You keeping an eye on DarkJak's rotor and caliper thread?