Hey, any chance you have that part number for the brake rotors? I noticed a few different ones on RockAuto from centric.Don't do it. First off, you'll bias the front differently. The OEM TT calipers are a matched set, engineered for the perfect front/rear bias. And they are already 4-piston. I run OEM TT calipers, Carbotech XP10 pads (front and rear), Centric Premium solid rotors, stainless steel brake lines, and Castrol SRF racing brake fluid. My car stops with the hand of god, and it's "full interior", including custom subwoofer enclosure. I cannot imagine any "better" braking performance than what I have. With this setup, braking technique (non-optimal) is the only thing that can make braking performance suffer. How would you describe/characterize your braking technique?
Spend your money on the nut behind the wheel first.
Are the Carbotech good on the street? Their website says not to use it for anything but track use.