All the answers about brakes

[Richard Hudgins]

Craig,

Well I will take a wild ass guess here as to your sizing.

With a 6.25 to 1 pedal ratio, 100 lbs pedal force gives you 625 lbs of MC force. (100 lbs pedal pressure is about where you wish to achieve lockup)

Therefore with the below MC sizes:

.625 dia = .3068 area 625 lbs force = 2037 psi line pressure.
.750 dia = .4418 area 625 lbs force = 1421 psi line pressure.
.875 dia = .6013 area 625 lbs force = 1039 psi line pressure.

Therefore with your caliper areas being:

front = 5.3967 sq. in.
@ 2037 psi = 10993 clamp pressure per rotor.
@ 1421 psi = 7668 clamp pressure per rotor.
@ 1039 psi = 5607 clamp pressure per rotor.

Rear = 2.9914 sq. in.
@ 2037 psi = 6093 clamp pressure per rotor.
@ 1421 psi = 4250 clamp pressure per rotor.
@ 1039 psi = 3108 clamp pressure per rotor.


Assuming a CG height of 17 inches and a 48-52 longitudinal location, the optimum F/R ratio for a one G stop is in the 1.2>1.35 to 1 range.

Looking at the pressure and clamp numbers above, it seems that you will need to use the .8750 diameter master cylinder for the front and the .750 for the rear. This will give you a F/R ratio of 1.31.

Also, the above combination will give about .55>.6 inch master cylinder travel for both units.

The balance bar will give you approximately a 1.6 to 1 adjustment range to fine tune to the bias.

In closing, the above information was compiled after a few adult beverages, therefore accuracy of information and the application of same must be checked by someone who has a clue, as I certainly do not.