What is the difference between the sizes of brake boosters, how much does it matter?

A 7" single diaphragm is for front drum ,rear drum set-up. A 7" dual diaphragm is for front disc, rear drum set-up, and the 8" dual diaphragm is for disc a/a.,which is what everyone wants. Four wheel disc brakes , thats what I'm talking about!!!!:thumbsup:The older I get the more concerned I get about stopping !

I don't mean to high jack the thread but I'm interested in the same area.


I have a manual brake set-up also with Classic Industries front disc set up. I want to add a booster on it and I happen to have an aftermarket one that is on my 71' camaro that I'm not using anymore. I was wondering if I could actually use that on my 64' Nova. Its like a "mini" booster when speaking in terms of the diameter, but its thicker than the stock booster that was on the camaro before. I figured it could just bolt on since both have the same exact dual diaphragm on them. Any info on this, I would great appreciate.

Thanks,
Smitty

The booster on your Camaro won't bolt to your Nova. We can provide you with a correct 9" 3 stud booster for your Nova for $99. Let me know if I can help.

Mike

The size of the booster (diaphragm area) is important to generate brake assist. Bigger is better (this assumes you don't really enjoy standing on the brake as a machismo kind of thing). The less vacuum your motor has (for example the bigger your cam; with a greater number of degree's of overlap) the bigger the booster diaphragm area has to be to generate the same line pressure. If you have a really, really radical cam with next to no manifold vacuum it reaches a point where you have to look to a Hydraboost (a brake system designed for diesel engines that run at atmospheric manifold pressure) to do the work for you. Otherwise, to get a bigger vacuum booster and you are restricted by the diameter (the motor and the vacuum booster have to share real estate space under the hood) then the next step is to double up as with a dual diaphragm. This will double the surface area and halve the pedal effort in a stock application, and make a marginal application viable.

Big Dave