Another Master Bore Question

[highschool70ss]

I am having a problem with not enough brake pressure. I can't even lock up the wheels. I am running baer serious street front and iron sport rear kits. I have a 8in. dual diaphragm booster with a wilwood 1in. bore master. Does anyone have a suggestion of what my problem could be.

[Apogee]

My guess would be that you're not generating enough pressure at the calipers due to an oversized master cylinder and undersized booster. Pad coefficient of friction (CoF) could definitely play a part as well.

Do you have access to a brake caliper pressure guage kit so that you can test your system?



Tobin
KORE3

[highschool70ss]

Do you have access to a brake caliper pressure guage kit so that you can test your system?

Tobin
KORE3

No I don't, where would I get such a thing. Do you think a .875 bore master would make a difference.

[Apogee]

Summit carries guages from several sources, including Strange, Wilwood, and SSBC, although there are many others as well. The guages thread onto an adapter that gets installed in place of the bleed screw fittings, so make sure that the kit includes the proper adapter fittings if you get one.

A 7/8" bore MC would be a much better choice assuming that the rear calipers are at least somewhere close to having 45mm diameter pistons. IIRC, the C4 Corvettes ran dual 9" boosters and a 7/8" bore MC, so that's more or less the base line for comparison with twin-38mm piston front calipers and single-45mm rears, only your dual 8" booster is going to provide about 25% less gain than the C4 unit.

Tobin
KORE3

[67ls]

what should the pressure be at the calipers with the car running