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cparman · 05-21-2010, 09:35 PM

Get a vacuum gauge. You need 17" of vacuum to get a vacuum power booster to work correctly. That is IF:

you are running a 9" or larger Vacuum booster
you have the pivot and the fulcrum figured correctly
You engine is a good state of tune

I have a 330 HP crate motor, and have 18" of vacuum. The 8" dual diaphram booster sucked. The 9" gives me great brakes.

Go to one of the brake companies sites and read about where to drill the new hole in the brake pedal to get the 4 two one ratio for power brakes.

Check your tune up, and see IF by adjusting the timing you can get more engine vacuum WITHOUT giving up the horsepower.

My $.02 is that you will find 7"-10" of vacuum, and that a vacuum pump will get you where you need to be. I like a 9" booster over the 8"
HTH
Chip

BTW hydro boost was a lousy idea in the 80's. I am sure that technology has made it better, but the pedal feel never appealed to me

05-21-2010, 09:35 PM	#5
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: hydro or vacuum pump?? BRAKES Get a vacuum gauge. You need 17" of vacuum to get a vacuum power booster to work correctly. That is IF: you are running a 9" or larger Vacuum booster you have the pivot and the fulcrum figured correctly You engine is a good state of tune I have a 330 HP crate motor, and have 18" of vacuum. The 8" dual diaphram booster sucked. The 9" gives me great brakes. Go to one of the brake companies sites and read about where to drill the new hole in the brake pedal to get the 4 two one ratio for power brakes. Check your tune up, and see IF by adjusting the timing you can get more engine vacuum WITHOUT giving up the horsepower. My $.02 is that you will find 7"-10" of vacuum, and that a vacuum pump will get you where you need to be. I like a 9" booster over the 8" HTH Chip BTW hydro boost was a lousy idea in the 80's. I am sure that technology has made it better, but the pedal feel never appealed to me Last edited by cparman; 05-21-2010 at 09:37 PM.