Hi, Bit of advice please:
What size master cylinders are recommended for following:
MK2 Escort Tarmac rally car
13" wheels
AP Monte Carlo 4 posts at front CP2270
AP CP2382 2 pot vented rears
Dual circuit pedal box
Thanks
Hi, Bit of advice please:
What size master cylinders are recommended for following:
MK2 Escort Tarmac rally car
13" wheels
AP Monte Carlo 4 posts at front CP2270
AP CP2382 2 pot vented rears
Dual circuit pedal box
Thanks
welcome to the mine field! get ready for 26 different answers, the trouble is personal preference also comes into it, some like a really solid pedal with little movement, other prefer more movement and more feel.
the usual starting point would be 0.6 front 0.7 rear
Last edited by Graham; 30-12-2021 at 18:02.
That would be my starting point too. You might also possibly need an inline bias valve for the rear brakes to stop them locking up.
Getting an ideal setting with a bias pedal box is a minefield and often takes many attempts to get to your liking. You probably won't even know it they are right until the brake pads get up to working temperature on an event.
Last edited by Forest_rallying; 30-12-2021 at 21:16.
Thanks, Mine has .7 in front & rear & I'm struggling to get enough to the front.
Will try a .6 in front.
Simple rule small number = higher pressure but lower volume moved & larger number = lower pressure but higher volume moved.
The difficulties occur in matching this simple rule to the slave cylinder diameter or caliper piston areas as there is no set rule for this due to pedal force differences, pedal feel, weight of vehicle and overall brake efficiency. BTW 0.6" isn't a commonly available size, that would be 0.625" and then 0.5" (rarer). Going larger sizes are 0.75" and 0.875" (rarer). Throw servo assistance into the mix and everything goes out the window as regards feel and pressure BUT a servo won't make bad brakes or poorly selected cylinders, better - just softer to operate!
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