The braking force is proportional to the pressure exerted on the pistons (and the size of the pistons).
This force is transmitted through the tyres, unless they lose grip.
So, bigger pistons and disks and harder braking all cause you to stop faster, to a point.
Beyond that point, softer-larger-more tyres are required to reduce stopping distances.
However, adding mbutt to the vehicle causes it to take more energy to reach a given speed, and so need more braking force to stop it. Helpfully, the tyres have a better grip on the road due to having more force pushing them down.
In fact, it does seem like the extra grip would cancel out the extra kinetic energy.
Hmm..
Ek = E
1-2 m v^2 = F d
1-2 m v^2 = Cf m A d
d = v^2 (2 Cf A)
So apparantly, stopping distance (buttuming brakes capable of locking the wheels) is proportional to v^2, and inversely proportional to the co-efficient of friction and the contact area of the tyre.
Then again, according to basic physics, parachutes fall at the same rate as lead blocks.
-- David Taylor
