[LJSMITH1]

Does anyone know why the OEM style BMW pads have multiple grooves cut in the pads?

I purchased and installed Carbone Lorraine pads which had a single groove down the center of each pad.

While the braking is fine and without squealing, I do hear a 'whine' or 'hum' similar to a decelerating turbine when I brake (actually its more like a 'zzzzzzzzz' sound). Its definitely coming from the front brakes. I think it has to do with the drilled front rotors and the single slot in the pads.

My theory is that the OEM pads have the multiple groves cut in them to address this very complaint. If not, why are the additional grooves there?

Thoughts? Comments?

 

[LJSMITH1]

Cooling of the Pad/Rotor. That is why high performance rotors are drilled & slotted.

That explains why the rotors are drilled. It has nothing to do with why the pads have slots on them.

The interesting thing is the grooves are not symmetrical on the length of the pad. This leads me to believe that they are designed to change the harmonics of the drilled holes in the rotor sliding by.