upgrade master brake cylinder
An 1-1/8" master will be a significant increase in pedal effort. That's even larger than the factory manual master cylinders which are 1-1/32". To me, even the 1-1/32" stock manual master results in a pretty hard pedal. Changing the stock master out for a 15/16" changes the pedal effort dramatically, although it does increase the amount of travel needed. The smaller bore results in a higher brake line pressure and a longer pedal stroke. The larger bore reduces line pressure and reduces the pedal stroke, but that means all the force has to be applied over a short pedal distance, which gives the high effort. There's no way I'd run a master cylinder bore that was larger than the factory 1-1/32" with the factory brakes, that will make the effort even higher and I already swap the stockers for 15/16" on all my cars.
Here's a picture of the DoctorDiff master cylinder in my Duster. The hydraulic clutch master cylinder is to the right of it and my adjustable prop valve is below it.
An 1-1/8" master will be a significant increase in pedal effort. That's even larger than the factory manual master cylinders which are 1-1/32". To me, even the 1-1/32" stock manual master results in a pretty hard pedal. Changing the stock master out for a 15/16" changes the pedal effort dramatically, although it does increase the amount of travel needed. The smaller bore results in a higher brake line pressure and a longer pedal stroke. The larger bore reduces line pressure and reduces the pedal stroke, but that means all the force has to be applied over a short pedal distance, which gives the high effort. There's no way I'd run a master cylinder bore that was larger than the factory 1-1/32" with the factory brakes, that will make the effort even higher and I already swap the stockers for 15/16" on all my cars.
Here's a picture of the DoctorDiff master cylinder in my Duster. The hydraulic clutch master cylinder is to the right of it and my adjustable prop valve is below it.