I was wondering if anyone has an idea of how long it takes for your brake pads and rotors to heatup and cool down during a session at the track. I imagine the rotors store more heat and therefore take longer to cool off, but what about the pads?

If you were to look at a chart of your pad temperatures over the course of a 20 min session, would you see a gradual and slow increase in temp until the end of the session, or could you look at the graph and see sharp peaks at the end of the front and back straight, with them cooling off realatively quickly? Are they mostly cooled by the next hard braking zone?

Just curious...

 

On-track, the chart you propose generally depends upon the venting (via air ducts, natural aero features on the vehicle, and wheel size/design). It also depends upon air temp and surface temp, of course. But I would generally say that pads dissipate heat better and more quickly than rotors, due to their generally softer (i.e. more porous) construction. And I would hypothesize that they gain and maintain 75%+ of their peak temps quickly, and throughout each session.

FWIW, many endurance-racer sportscars get their rotors so hot that they glow red for 1-2 seconds under hard braking, then cool back down to "normal metal color" until the next hard braking zone. I've seen this on everything from pro ALMS Porsches to club-level Showroom Stock machines, during enduros in each instance. It's so cool to watch.

Hope that helps,

Jon

 

My brakes are usually warmed up 99% within two laps of starting a session. I give them quite a few hard jabs during the formation lap, the 1st race lap can be a bit hairy, and by lap two of the race, they are hot.

As Jon said, brakes warm and cool considerably during sessions. Especially enduro type events, where there are no cool down periods. They won't be "mostly cooled" between brake zones, but they will be less hot.

As for cool down after a session, a lap with no brakes followed by a few laps of the paddock should get brakes cool enough to park. But not cool enough to handle without gloves.