what size master cly would you folks recommend? no power brakes... brembo calipers from a 2000 porsche boxster.. the bolt to the mount is alfa romeo spider.. but i found i could use a m/c from some bmw;s... i re welded and drilled the pedal arm to no power brake ration... i have used the front porsche/ brembo calipers on the front and the stock 2 piston oem , before i started my ecotec conversion project.. without boost and i could stop the car pretty easy i think the m/c on the car now is 22 mm..i will check to, and repost tomorrow.. just looking for ideas for new set up...
Honsch
Reader
4/10/21 2:21 a.m.
Sounds like you need to do the math.
How much brake torque to you need?
What size rotors will you use?
What mu pads are you going to run?
What's the piston area of the calipers?
With that info you can get a good estimate of how much brake fluid PSI you need.
Once you have that you can do the other side math:
How much pedal pressure do you want to generate full brake torque?
What's the lever arm ratio for the brake pedal?
Now you can determine the piston area of the master cylinder to generate the required PSI with the force applied.
Other concerns include:
Amount of pedal travel available and will it be enough to generate full pressure under all conditions?
How many fluid circuits?
How will you be adjusting bias?
Are the front and rear PSI requirements close enough to allow bias adjustment?
How much fluid does the MC reservoir hold and is it enough volume for full pad wear?
Without doing at least estimates of all this you'll be buying several master cylinders to get something useable.
i just was looking for a starting point
I'd start by matching the MC to the front calipers, then figuring out how hard I was willing to push the pedal to achieve lockup. If it's a track car on track tires, figure you'll want your system to generate 1.2-ish g decel.
there was an article in the June 2008 issue that has all the equations.
