Had the top down for the first time this year yesterday. I got out of my car and I was looking at the wheels. The rear wheels had a lot of brake dust on them, whereas the fronts had hardly any. Also, the car feels like its got too much bias for the back wheels. I want to adjust my proportioning valve, the car has a turbo coupe rear end in it, w/ 3.55's and 4 wheel disc. What is the proper way to do this? Also, on the proportioning valve, there is an "increase," and a "decrease." Does "decrease" mean "decrease" rear bias?