I drilled a hole up higher on my brake arm and built the plate to bolt my master cylinder to the firewall..as well as an adjustable brake push rod. I'm still using the old master cylinder and am wondering how shitty it's gonna be. car is about 2 weeks away from moving under its own power.. who has done this and how bad was it. I have no vacume and the ugly vacuume booster was always in my way...

 

Depends upon how far up the new hole is in the pedal arm. But at the same time most likely will need a M/C with a smaller bore.

RBob.

 

Ok guys well I just measured and I moved the brake rod up the arm 2.1 inches from the stock location. I found an old school pressure guage and hit 2100 psi whe really standing on the brakes. Pressing firmly I easily hit 1400psi so I'm going to go ahead and try it since all my brake lines are ran to my mc.... Anybody have any more input on this.... What would most manual master cylinders hit for psi

 

I think the hole may be too far up the pedal arm. 2100 psi is on the high side by almost double what is required. Should be around 1200 psi when hard on the pedal. If that gauge is correct caliper flex is going to be a major issue.

The typical pedal to rod position ratio for manual brakes is 6:1.

Good braking information can be found here:

http://www.stoptech.com/tech_info/te...e_papers.shtml

The article "Brake Pedal Setup and Dual Master Cylinder Installation Guide" explains how to calculate the pedal ratio. Easy to do, just get two measurements on the pedal arm and divide one into the other.

RBob.

 

Very good read a guy could spend hours on there. That's the kind of information I love finding off this site.... I'm still gonna just run my setup if it locks up too easily I will move my brake pushrod further down the brake arm itself.

 

hey 85berlinetta383, I know this thread's a little old how did that end up for you? i'm looking to do manual brakes with a stock setup too. Can we get some more info on what worked/didn't work for you in the end?