The last track day I went to in September, I started getting a nasty vibration through the car during braking. This happened my very first run on maybe the 4th lap.

In subsequent runs, the problem persisted. My instructor agreed that it sounded/felt like I had a warped rotor. It would vibrate slowing from 125 mph to 80 mph and even slowing from 70 mph to 50 mph. Even on light braking, the vibration continued.

We checked the brake pads and confirmed there was plenty of pad on all four corners. I kind of wrote off the rest of the day and ran slow laps as the vibration continued.

Driving the car home, I had no vibration issues under normal braking. A week later, I tested it with hard braking. No vibration whatsover. This leads me to believe I did not warp a rotor.

So my question is: What is wrong with my brakes? I assume I'll encounter this next track day and don't want to miss out on a good day. At the same time, I don't have the money (read: approval from wife) to buy all sorts of brake parts.

Can anyone help me evaluate the issue? My brakes are completely stock, FYI.

On a secondary note, is it common to through out your alignment if/when you spin out? The first time I spun I was on springs only; the steering became slightly right-biased after than. The second time I spun was on Spoon coilovers; the steering became slightly left-biased and I noticed my right wheel gap is bigger than my left.

Any reasons?

TIA

Thanks.

 

Could be improperly torqued lug nuts - under track conditions they pull asymmetrically, but not enough to permanently warp the rotors - when they cool down under regular use, it goes away. Perhaps a defective rotor, that shows suymptoms only when it gets really hot on the track?

Just an idea.