Quote: When you decrease the pedal ratio, you increase the stroke in the M/C. Power brakes systems use less pedal ratio, therefor more stroke at the MC for a given pedal travel. Same bore M/C going from manual to power sends out more volume for a given pedal travel. That's what is different.
I thought that the travel of the piston in the master cylinders was about the same. I might be operating on a "fuzzy memory" here, but when I bench bled the master cylinder, I bottomed out the piston. When I put the master cylinder in the car, it appeared that the with the brake pushrod in the M/C, it bottomed out only a fraction deeper than the brake pedals travel. I'm certain that you don't want the pedal to stop 2 inches off of the floor because the M/C ran out of stroke.
