RSD Big Brakes _ Looking to Improve Performance

[Michael101]

I currently have the RSD Signature 4 wheel big brake kit installed but I'm not satisfied with the performance thus far. I'm not saying that my dissatisfaction is with the RSD kit, it's more like I haven't found the sweet spot of master cylinder/booster set up yet. I chose not to use the master that came from RSD because I prefer newer style masters to go along with my LS swap. My current master cylinder is the ACDelco 18M2441 (97-04 Corvette) and I have a dual 8" booster and Wilwood proportioning valve. I've tried several different MS bore sizes but find that I'm in the same general performance area regardless of bore size. I use the Motive Products power bleeder and am fairly certain that I do not have air in my brake system.

What I'm experiencing is hard pedal and what I'd say is diminished stopping power. I'm wondering if I'm on the borderline of proper functionality with the vacuum booster because my idle vacuum is around 15". I've also read post that suggest switching the master cylinder outlets front/rear (on S10 masters) and wondering if I might have mine routed wrong (front/front, rear/rear).

I appreciate any thoughts or ideas.

[1bad68cat]

What I'm experiencing is hard pedal and what I'd say is diminished stopping power. I'm wondering if I'm on the borderline of proper functionality with the vacuum booster because my idle vacuum is around 15".

These two things point to a vacuum booster issue. The first may be a defective booster, but after seeing that you only get 15" of vacuum I'd lean toward the second issue. Booster typically needs at least 18" of vacuum. While parked, try hooking up a vacuum pump w/ gauge to the brake booster and see how the pedal feels when you apply the brakes. It should feel noticeably different just sitting there.

[TheJDMan]

At 15" of vacuum you may be a candidate for hydro-boost. You also did not mention what pads you're running. You can tailor your brake performance with different pad compounds.