For starters, my car is a mid-engine locost. It has a VQ30de v6 mid mounted in the rear with the front calipers from a 1997 maxima in the rear. (piston sized 57.2mm) The front brakes are from a 90-93 miata 51mm piston.
I tried to adapt my factory brake pedal master cylinder to my car. When it did drive the results were somewhat disastrous. The fronts would lock under light braking, the rears wouldn't lock at all. The pedal arc is way off and every time I push the brake pedal my knee bends and my foot has to push forward to engage the brake. The maxima brakes had a booster and a 15/16 master cylinder.
I put a proportioning valve on the front brakes and that improved the performance of the brakes but not the ergonomics.
I also added a clutch pedal from an S2000, made it a reverse swing unit and it worked better, but I still had the funky ergonomics of having to push my foot forward rather than pivot my foot.
I found by rising the clutch pedal that fixed the ergonomics, but put the pedal mounts above the scuttle.
My solution is to by a clutch and brake pedal set. I have found they have two ratios 5:1 and 6:1. I'm leaning to the 6:1 but I have no idea what master cylinders to by for the brakes as it is a dual system. I have a fair amount of room to mount these pedals. Do I get equal sizes or stager them. The pedals I am looking at are from southwest speed.
http://www.southwestspeed.com/?sec=view_menu&cat=Hubs%20And%20Brakes&sub=Pedals&ssub=Brake%20and%20Clutch%20Pedal%20Combo%20Kits%20With%20M/C&sssub=Reverse%20Swing%20Mount-Long. They have daul masters with a balance bar. The sizes they have available are 3/4", 7/8", & 1.
Thanks
evo