I spent two great track days at Thunderhill last weekend
In the middle of day #2 the following started to happen:
When the brakes were hot and I was doing heavy breaking from high speeds (example breaking from ~ 115 mph for turn 1 or at turn 9 or turn 14) the car felt like I was braking on a "washboard" surface, meaning that the car became a bit unstable and started to "wobble"
This was NOT the ABS, which feels different, I also did not have brake fading and I had pretty much the same brake distance as before, so the brakes generally still worked great. And it only happened after a few laps when the brakes were hot.
My best guess is that I have warped rotor(s) in the front, so before I go out and buy new rotors, here are my questions:
a) does anyone have a better idea?
b) is there a way to test if I have warped rotors
c) why would that only happen when the brakes are hot?
P.S.: I see no cracks in the rotors
P.P.S: Nobody else seemed to have that problem, so I am sure it was not the surface of the track itself