Some issues from a 2-day HPDE...

Sharif@Forged

The most important thing, is that you have the correct brake pad (heat range) for your intended driving and vehicle/setup. The only way to accurately determine this is with a pyrometer and/or temp paint. I can make a recommendation this is going to be close, but it won't be perfect without feedback from the driver and some carefull data collection. Since we track many of the same lines of cars over and over again, we've got a pretty good baseline as to what works and what doesn't.

To the OP, the vibration you are feeling could be warpage or deposits as others have alluded to. Keep in mind, your brakes and rotors will be happiest if you use them HARD for the shortest period of time. If you feather the brakes at any point on the track or brake softly and then increase pressure as the braking zone ends then you will likely continue to have some vibration as you will not be applying enough pressure to uniformly transfer material to your rotors.

__________________
Sharif@Forgedperformance.com
General Manager/Certified Tuner/NASA-PCA-BMWCAA Instructor
JRZ RS1's Available NOW...PM me
Cobb ProTuner, Uprev ECU Flash, FCON Vpro, Haltech, Motec Certified