need an education 7" Vacuum Booster

Ok
what is the difference , and need for a "dual diaphram booster" VS a single diaphram booster?


why would one be specified over the other?
are the dual set ups for heavy vehicles?

or is it that needing the 7" unit to go under the floor of a hot rod..using a 7" dual gives you the stopping power of a 10" single diaphram system...i think im spelling that wrong "diaphragm"..thats it

 

bump?

 

The surface area of a single 7" doesn't put out enough power. With dual 7"ers you get enough pull. I have a dual 7" on my Merc and am replacing it (and a few more parts) this winter for a larger one.

 

Is this for an under floor or firewall set-up? If firewall I'd go to a bigger unit. Personally I don't have much faith in the small units especially aftermarket ones.

 

Under the floor in an A..thats the reason for the 7"..

I guess i should look at it as ..how much boost do I really need? probably not alot for an A sedan.

 

You probably don't need any boost. I had disc brakes on my 50 chevy truck, it stopped great with no power booster.

 

The 7" booster was originally designed for the Chevette. Very light car with good vacuum signal