Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Anyone got any experience with speccing master cylinder size?


ClioSport Club Member
Does anyone have access to a good calculator for this, or able to give me some guidance?

A couple of drives in my car have revealed that the brake pedal is pretty long. I need to bed the pads in, so the brakes aren't brilliant obviously, but there seems to be a lot of pedal travel regardless. Pretty certain I have no air in the system, so I am wondering if I need to change a master cylinder.

Am running a 0.75" front, 0.875" rear, four pot calipers on 325mm discs up front (2x 36mm, 2x 40mm piston), 260mm rears with twin piston calipers.

In "rule of thumb" land, a 0.75" front cylinder seems about right, but I'd like a harder pedal really.

Any thoughts?


ClioSport Club Member
@massivewangers what setup are you running? I have ap racing mcs to go in with a Tilton, I want a hard pedal as well but don’t know what to expect as never driven with one before.


ClioSport Club Member
i think you need the diameter of the brake pistons (or surface area actually)
add them up, and the decide which ratio you want (ie same surface is 1:1, 2:1 etc first in this example is calipers, second mbc)

what calipers are they?
if from another car, you could use that as a starting point and go UP from there.