TBone, I am writing you outside of the brake pad thread in an effort to not sound like a braggart or an idiot. I run in group A. I run flat out. That is how I drive. HaHa. Obviously I am mocking the RA driver brief., as it was very good, and funny. I do drive fairly hard, but strive to be smooth, and hit my marks. The last car I took to RA was an 08 Z06. No brake upgrade needed. They were awesome, and did not fade lap after lap. Before that I took an 04 Z06, good brakes but they would begin to fade on lap 3. Now I have a 13 ZL1. Brakes are not very good due to pad compound, and weight of car, and weight of rotating mass. My main question is for the rear pad. Have you ran the xr1 fronts with the either the xr2, or xr3 in rear for comparison? If so what is your preference.