Brake Booster Size

[footballubet]

What are the advantages and disadvantages of going with a 9" brake booster. I'm thinking about using the 9" just to clean up the engine bay a little bit. Don't need it for room, as I'm running a SB. Just wondering about less reserve vacuum that's all.

 

Give me your thoughts.

Thanks

[monte70car]

i would say room around the valve cover scott. but i could be wrong

[kc8oye]

less power assist too.. unless you run a dual-diapragm.. there is another post in modifiers I believe discussing this. search for brake boosters

 

[bobsmc]

http://cgi.ebay.com/ebaymotors/67-72-Che...1QQcmdZViewItem

 

this is the set up i put on mine.

make him a low ball offer.

i think i paid 229.

nice stuff works good and looks great.

[footballubet]

Looks like a nice set up, and I don't need the lines and proportioning valve. Might just try that.

[Reaper]

I bought a chroms dual booster that is 7" I think with the master cylinder for about that off ebay... might be 8" but it works and looks good. The master cylinder has two screws in the top of it instead of the bar that slides over the top. If I think about it I will take a pic....

Tom

[bobsmc]

the guy i bought my stuff off was local .

i bought it off ebay but went and picked it up.

 

[footballubet]

He won't take less than $290...Big savings off the "Buy it Now" price of $299

[DavidTX]

If you have a stock cam you can get by with the smaller booster. With a larger cam, you will have less vacuum and can have problems.

[Reaper]

I use a canister and my brakes still arent the best but they work Dont really think its from lack of vacuum though... just bad luck with brakes.

[kc8oye]

one thing about low vacuum is trying to set your idle speed too low!!!

 

I have a pretty mild cam.. but when I had the idle speed down to 500rpm in gear, the pedal was noticbly harder (13" of vac) then when I had the idle @ 750 (16" vac)

 

big cams need to idle fast.. that's where high stall converters are nice too

 

[Heckeng]

I just swapped out my stock booster for a dual diaphragm 8" unit. I am disappointed to say that the performance was better with the stock unit. I am running around 10 inches of vacuum at idle, which is not quite enough for the dual 8" booster. The positive side is that I have cleaned up the engine compartment nicely. I will be getting an electric vacuum pump to clutter things back up now