Watching this sport a long time and I've seen calipers lock up. Pads disintegrate and other things to cause the rear rotor to glow and from time to time spark, even seen rotors explode.

But every race I've seen Macri in this year that rear brake is sparking, glowing. looks like somethings off center.

Anyone know? Just carbon fiber disintegration? IDK.

I thought it was a James Bond distraction technique

Happens frequently with the 39 car, I don’t know why
It doesn’t seem to slow him down or hurt him any

I have noticed it also, what used to be "that guys brakes are about fried" now goes on lap after lap.

My friend says it's the pads everyone is using? I have no idea. I know one rear brake unit did catch fire while I was watching the Larry Rice Classic a few weeks ago. Forget the driver but he pulled off and went back to his pit.

Pad and rotor combo mostly. Might also have a lot of rear bias as well

Looked like the hot set up to me!

Most likely he has a titanium rotor,the hotter they get the better they work.

Best guess would be titanium rotors. =$$$🤔

Diamond infused rotor w/Concrete (Macri) pads.

Think Macri is experimenting with carbon fiber rotors.