Keeping up with your race car maintenance is critical, and brakes should be at the top of your list. I take a look at my rotors and pads after every event, and keep track of my maintenance in a notebook so I can spot trends over time. These front brake rotors are two seasons old (ten weekends), and have been through two sets of brake pads. I use stock vented 280ZX front rotors on my 510 as they are easy to find (my local NAPA) and inexpensive to replace ($70/pair). “Performance” OE rotors are available through companies like Baer and SP with options like drilled, slotted, and cryo-treated but cost up to $350/pair, so I haven’t chosen to go that way yet. I also run cooling ducts from the front spoiler, and aim the airflow to the center of the backs of the rotors.
The heat cracking seen in the first photo starts after just the first weekend of use, and slowly grows in size. The large crack seen in the second photo occurred since the last inspection, and led to this service. I have now replaced the rotors and pads, and cleaned, inspected, and repacked the wheel bearings with hi-temp grease. After two years the rotors have barely decreased in thickness, from .79″ (20mm) to .78″, far from the recommended minimum thickness .71″ (18mm). I replace the brake pads when the friction material is worn to about 50% as the heat dissipation properties drops below that point, these rotors lasted for two sets of pads.
I agree that brakes should be at the top of your maintenance list. Not being able to go is an annoyance, but not being able to stop can be scary. I really like how you keep track of your maintenance in a notebook so you can catch any trends. I think I will start doing that with my car and see if it helps reduce the amount of problems that come up. Thanks for sharing this experience!