[PeteMachinist]

What is the difference betwwen a single or dual diaphram brake booster. What seems to be the general consensus on which one to use on a streetrod. Thanks everyone. I sure enjoy being a member here, the knowledge and experience that you all share with us newbie rodders is greatly appreciated. One has to really respect what the rodders of years gone by learned and figured out. Now we have the internet and it has made things a lot easier for newcomers..

Thanks

Pete

[yesgo]

Dual diaphragm is also called dual stage. It offers extra boost, but can make for a squishy pedal IMO. People like to use them because you can run a smaller diameter booster. Also/or, they can run a large bore master cylinder.
The size/volume of the booster normally determines the amount of assist, but with a dual diaphragm, you can run a 7" diameter and get near the same assist as you would from a larger single stage, say, 11". The pedal feel is different though because it goes thru 2 stages of assist.

You run whatever fits best, looks right, and is suited to your own personal taste. Mostly it's about fit and function.