Quote:
Originally posted by Dick Young
I've searched and can't find the answer - how exactly does drilling and slotting improve performance of a brake rotor?
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To put it in the short version. The slotting is to allow air or gas to escape, out from between the pad and rotor. Otherwise the gas will float the pad on the disk to produce fade, this is mainly for racing as the pads won't get that hot, under normal road use. For road use, the slotting will help, to reduce the squealing, that happens when air is trapped between the pad and rotor.
The drilling is to allow water to escape from between the pad and rotor. Used on mainly on motor cycles because the disks are open to the rain. It allows the water to be squeezed into the holes, away from the surface of the disk. The bike riders will know the feeling, of hitting the front brake in the wet, to have no reaction, so you squeeze harder, the water goes, the brake locks and down the road you go.
On our road cars the disk is shrouded by the wheel, so the water is not a problem and the holes are not needed. Only solid disks should be drilled. Drilling vented disks interferes with the cooling, that the vents are designed to do. You would not drill holes in the impeller housing of a turbo charger as it would interfere with it's action. The venting between the surfaces works the same as the impeller, to pump air from the center of the disk to the outside edge to provide even cooling of the disk.
Though you can get them in 4 different colours and with blue callipers they work fantastic at pulling a crowd.
Harvey.
