Spoke to AP Racing today, after my brake issues on Saturday, and they confirmed the factory AP front pads are strictly road use only, and too soft a compound for track use. I have had to refit the plain factory discs and a new set of AP pads today as my groovy Black Diamond discs will need refacing, and I need to get some Ferodo pads for the next trackday. Will also sort some serious cooling ducts which I should have done sooner.