Why do brake discs turn red/orange?

Like the first answerer said it's heat from friction caused by their hard braking when going from a straight away to a corner, racers are trying to get around the corner as fast as possible without losing control and when your braking a lot to get a car down from 100mph or more to 40mph your brakes better be good cause they will heat up like nothing else.

Imagine touching one of those red hot brake rotors bwahaha....ouch.

It is because they are glowing red hot from the friction generated between the discs and the pads.

Quite normal in high performance cars and braking sytems.

Heat I've worked on glowing red hot disks on

rally cars where their discs would easily

burn, as such I was quick used lighting and the

occasional friendly persuader.

I didn't need much light.

Best Wishes.

Mars Mission.

32 Years Qual Mech.

On a race car, if the discs are glowing red, you aren't racing hard enough.

friction rub your hands together they wil get hot same thing brake pad rubbing on brake rotor