Help !!!!Brakes & Master Cylinder

[rdorman]

Originally Posted by Jerry Clayton

with a pedal ratio you stated of 6.5 to 1---you are only moving the master aprox 1 in with 6 in pedal travel--a 3/4 master won't displace enough fluid to fill your calipers---you need to get bigger masters

Not to disagree with Rman but your problem at this point is strictly hydraulics---c-g and g forces don't apply---yet--

Jerry

Not a problem Jerry. The 3/4 master will travel about .22" and the rear about .14" for a optimal amount of radial run out (kicking the piston back) and deflection (zero!). That is on a 1.1" max travel for tilton master cylinders. I never would get any where near close to that max number for obvious reasons! Not sure what you mean by 'your problem'. If you are talking about the intermittant pedal he is having, yes, it is some form of hyraulic or mechanical problem. If you are refering to my working with master cylinder sizes, then actually I use CG, various CFs, aero loading, weight transfer, etc, etc, etc to play with different sizes.

My issue with recommending master cylinder sizes at the moment is CG height is unknown and he has another issue that needs to be resolved. Additionally, he states that no matter how hard he pushes, he can not lock the brakes. Assuming that all is right (and we know it is not), I would be leaning him towards smaller MC's (at least in the front). I have a similar setup in my Cobra on the front and the MC is a 5/8's and works very nicely with minimal travel (about 2" total). Same calipers, pedal ratio, etc.