I was just doing some searching,and it does appear the race cars have R8 rear brakes for the front brakes.
After that track day,I was talking to a local guy who was at one point on one of the support crews for these cars.He was the one who told me about the R8 brakes,but he also didn't seem like the brightest guy

*edit*Found an article where Eurotuner drove one,and it talks about the R8 brakes:
http://eurotuner.automotive.com/8569...ent/index.html
Also found a Car & Driver article along the same lines,although it says the 14"(!) rotors are from the front of the R8.I'm too lazy to search and see if the R8 front or rear brakes are 14".