Upgrade Brake Master Cylinder

[Ivan141]

The extra area of the piston makes it possible to displace more fluid with less pedal travel. When you think of it, it's pretty logical that you will need to apply more pedal force to reach the same pressures with that decreased pedal travel. It is not the volume that you displace that defines the braking force, since you already displace maximum volume with your stock system (otherwise it wouldnt work now would it?). It's the compression of the brake fluid that does the actual work.
Pressure is a function of force and area, the bigger the area you apply force on, the more force you need to get a certain pressure. The only way to really get the brakes to clamp harder is to raise the pressure, which means you'll need to press that pedal harder. With a bigger than stock master cilinder, that means that you will need to press the brakes a lot harder to get any improvement.

The advantages to having a bigger master cilinder IMO are:
-more fluid to account for flex in the brake system..
-more pedal pressure, making it easier to dose the power you put in.

Getting the car to actually brake better (not just feel better) is in theory more up to the brake pads and heat capacity of your system. And ultimately the grip of your tyres is what really stops your car.