power or manual brakes

Braking power of a vehicle is based on the surface area of the friction surfaces and hydraulic mechanism (drum width, diameter & shoe size, disc diameter & pad size, caliper piston, wheel cylinder & master cylinder area. The booster does nothing more than assist in applying the brakes. If you take the booster off a car and change nothing else the vehicle will have the same amount of stopping power but the driver will have to use more effort to apply the same amount of braking pressure. The reverse is also true, if you put a booster on a manual brake car and change nothing else the booster will only assist the driver in applying the same pressure to the brakes with less driver effort. For example my drag car has manual brakes and I can lock up the tires if I want, the booster can't do anything to help my braking if the brakes are locked.

Chuck