|When installing the larger rotors, we simply removed the front dust shields. We left the rear shields in place due to the rear drum parking brake. We did have to remove the lip on the dust shield to clear the rotor.
We replaced our front rotors with DBA’s top of the line 5000 series rotors. The 5000 series rotor is a two piece design featuring a lightweight aluminum center hat with a corrosion resistant black anodized finish. The aluminum center hat reduces unsprung and rotating weight by three pounds per rotor. This improves acceleration, braking and suspension performance. The rotor itself is available separately so the hat can be reused should the rotor wear out. The rotor is positively held to the hat with aerospace NAS bolts solidly, not floating. Although the 5000 series rotor comes in a cross drilled configuration we opted for a less likely to crack slotted surface.
|Howard Watanabe of Technosquare removes the lip with a cut off wheel.
When brakes are used at high speeds, typically with new street type brake pads, the surface of the brake pad material vaporizes or out gasses and the pad can hydroplane on the layer of gaseous vaporized brake pad. This can make the brakes less effective. This type of brake fade is often encountered, with new unbedded street brake pads, not so much with race type pads. Race pads have a different surface interaction but that’s a whole different story.
|Here is the rear dust shield with the lip removed and the rotor ready to install.
Holes drilled into the surface of the rotor give the gas and pad material somewhere to go, reducing the hydroplaning effect and eliminating this type of brake fade. The trouble is, although drilled rotors look sexy, they often crack between the holes. Thus for track use, many feel that a slotted rotor is better. The slots act like tread on a tire and give the gas and spent pad material a place to go. The slots do not have any tendency to crack. For this reason we decided to go with slotted rotors. Slots also tend to reduce the brake pads tendency to glaze and help wet performance as well as they give water somewhere to go helping reduce the pads tendency to hydroplane on a layer of water.