Originally Posted by
ddd4114
Well, depending on the situation, it might not help. For example, if your brakes can produce 1000 lb of force, but the max friction force of the tire is 900 lb, a 3% reduction in area won't really matter. Plus, the coefficient of friction doesn't drop as quickly at higher temperatures with drilled rotors, so a blank rotor could drop below the 900 lb threshold at a lower temperature than a drilled rotor. It is an oversimplified example, but you get the idea.
You're not going to get enough heat into your brakes in a 60 second autocross run to warrant any additional cooling. Another consideration is that cooler doesn't always mean better when it comes to braking. Different pads operate best at different temperatures, and there are plenty of pads out there (particularly performance pads), that work better hot than cold.