Manual Brake System Trouble Shooting: Expected Line Pressure?

[Payton King]

correctly size the masters to the calipers. May be hard in your case with drum rear brakes. Personally I would not run the proportioning valve.

Most calipers do not want more than 1200 psi. You can get some caliper pressure gauges from Longacre for about $100 for 2 gauges and a cool metal case. For C5 sized brakes front and rear I was getting 1100 psi front and 850-900 rear with about 100 lbs leg pressure. I ended up with a 3/4 front and 3/4 rear on mine, but the rear sizing was due to 335/19 tire that was 27 inches tall. It could take more rear brake and still be ballanced.

I am going to guess that your problem lies in what brake pad you have up front. If you are running a street pad, I would change to something more agressive. I tried the Wilwood BP10's and could not get my car to stop no matter what I tried. Went to a Carbotech Ax6 (autocross pad with good cold bite) and it was a night and day difference. They will be dusty and will make some noise. Mine never made any noise, but I have heard other people say they do.

I have not tried but heard good things about the Hawk HP+ as well.