In a message dated 8/1/02 11:37:02 AM Eastern Daylight Time, dmcman73@xxxx writes: << HUH? The front and Rear calipers are already on separate lines. They do not have a common pipe. One pipe for the two front calipers goes to one port of the brake Master Cylinder and the other pipe for the rear calipers goes to another port on the Master Cylinders. The ports on the Master Cylinders are already their own entity (separate from one another). >> I think the issue is this. Brakes transform inertia into heat. The more efficient the materials used to create heat from inertia, and transfer that heat to the atmosphere, the more efficient the brake. And the more efficient the brake, the less energy (pedal pressure) required to provide the same braking power. So highly efficient front rotors and calipers, used with stock rears, could create a situation where the front/rear braking efficiency balance is upset, and the fronts could lock up way ahead of the rears. So you'd want to lower the PSI to the fronts, relative to the rears in order to take advantage of thier higher efficiency, (Better feel, and no fade.), and still maintain a reasonable balance.....Just my opinion but it makes sense to me. Jim 6147