rotors are a hair over 12" and the willwood calipers are almost an inch narrower then the brembos, gold nissan brembos have to work on both the 12" sentra rotors AND teh much bigger 350Z track rotors. by actually speccifying the correct caliper (not one from the parts bin) I can now run my 16" wheels I want mabye smaller.. so I also am selling my 17x7 4x114.3 wheels with nearly new Hankook slicks, if you know anyone intrested. (they clear the brembos) and the tires have 1 autocross on them.