We tested both of our cars yesterday at NJMP Lightning in preparation for the Regional. My brother's car has been plagued with a vibration under braking since we bought it; sometimes it is better than others. He has replaced all 4 rotors and all 4 calipers. I drove his car yesterday after 2 sessions in my car and the vibration is as bad as ever. It is so violent that the steering wheel chatters enough hurt your wrists.
There are 2 heavy braking area on Lightning, entry to T1 and T7.
Here are some notes:
Approx 20% of the time, the brakes are fine.
Approx 30% of the time, there is not vibration under initial heavy braking, the brakes feel really good, but at the end of the braking event, the steering wheel suddenly vibrates.
Approx 50% of the time, the steering wheel vibrates upon brake application.
Hot or cold does not seem to matter.
Any ideas guys?