[__409__]

I have read about single and dual brake boosters, but they don't
talk about the difference in them, or the advantage\disadvantage of one over the other. I could you some help


Thanks

[nevermind]

Dual boosters? or Dual chamber master cylinder?...Cheers!

[powerrodsmike]

single boosters have 1 diaphragm, require a large diameter booster to generate a large force. A dual diaphragm unit with a comparable boosting force has a smaller overall diameter, but is longer than a single. The pros to a single is that it will fit closer to the firewall if that is where the available room is, and they are a little more efficient. The pros for the longer dual is that it will fit under the floor on a vehicle with a frame mounted master cylinder, or clear the valve cover in a tight engine compartment.
master power brakes has a cool info section on their website. Here is one of the pages that might help.
http://www.911brakes.com/midsizebooster.htm

here is the rest of that web page ,you may find it useful someday
http://www.911brakes.com/
hope this helps, mikey

[techinspector1]

Originally Posted by __409__

I have read about single and dual brake boosters, but they don't
talk about the difference in them, or the advantage\disadvantage of one over the other. I could you some help


Thanks

powerrodsmike has done a good job of explaining. The only thing I might add is to explain that it is all about square inches of area of the diaphragm. A larger diameter diaphragm will apply more pressure to the master than a smaller diameter diaphragm because it has more area acted on by the manifold vacuum of the motor. (Actually, it is the atmospheric pressure behind the diaphragm that moves it in the absence of pressure on the front of it as a result of negative pressure from the intake manifold). For instance, a 7" diaphragm will have 21.99 square inches of area, while an 8" diaphragm will have 25.13 square inches of area and a dual 8", such as needed for a disc/disc system will have over 50 square inches of area.