Last weekend had a chance to finally work on the brakes which have been a sore point on this car during our baseline autocross experiences in the fall. Long story short, we lost significant stopping power multiple times at an event down at Jones Beach when hot lapping the car with my father co-driving. Figured we boiled the brake fluid (it was black) and bled the brakes with ATE Superblue DOT 4 (which is now yellow?). This improved the situation somewhat, but we still had unresolved brake performance issues at the season finale event in Fairfield, CT.
Upon disassembly the factory performance package pads were extremely glazed and the rotors had some heat checking. Went to replace the factory rotors/pads with Centric Premium rotors & Porterfield R4-S pads, but ran into some unforeseen issues. After reading about the V6 PP I was under the impression that the front rotors were increased to the base GT 13.2's, but found my car was equipped with the smaller 12.4 rotors of the base v6 (I should've been more suspicious as the car came with 17 inch snow tires and no brake clearance issues). I'm wondering if the early build date of my car (9/28/10) might have something to do with the smaller rotors compared the the 13.2's listed as correct part on numerous sites?
A quick run to autozone netted a replacement set of Duralast Gold rotors in the proper size. Took the car out to bed the brakes with a few back to back 80-5mph runs to get the brakes hot and was happy with the newfound braking performance.
My prior experiences with the R4S has been positive as a solid mixed use pad for autox/daily use in NYC without too much dust and the guys at Porterfield have always been extremely helpful. Hoping the new setup can handle the weight/heat generated by this car, but won't know until the 2020 season resumes.
Koni Yellows should be going on the car within the next few weekends, praying that the stiffer shock/bumpstop setup mitigates some of the brake dive of the soft GT springs/80k mile original shocks...
FYI the 2013-2014 Mustang 3.7 V6 PP automatic transmission chassis only had 13.2” front rotors, all the manual transmission 3.7 V6 PP cars have the same size front rotors as all other model 11-14 3.7 V6 as you found out.