caliper and disc upgrade. How big of a disc are you using? I'm thinking 280mm on mine but wonder what is the minimum size disc I can use with this upgrade? 275mm? 270mm? I'm thinking of having Compbrake make a custon rotor and disc for me. Opinions? I'm trying to avoid having to install a Tilton brake proportion valve or something to that effect because the disc may throw the balance off. 
Oh and my front discs are 309mm! with Boxster Brembos.
Oh and my front discs are 309mm! with Boxster Brembos.