Euro S50 and Brake Boosters

[Mike B.]

Lee,

With the dual master in a single body setup, the spacing between the two shafts is too narrow for the integration of a balance bar. There would not be enough adjustment before you end up with binding. The only way to control bias with this setup is with an adjustable bias valve plumbed into the rear brake line.

[Mike B.]

beautiful! Do you ever make it out to the track? I'm in your area and would love to see your setup sometime.

I'll be running the full course at Autobahn with AMS (of EVO fame) on April 28th.

[2002maniac]

I'm not even planning on a swap in the near future, but here's my manual brake adapter that I made in my spare time at work. Unfortunately I cant make more to sell (even though the cost would be prohibitively high), my boss doesnt want me using his machines for side jobs that put money in my pocket. It started out as a 5" round 6061 billet.

[Mike B.]

Nice! Why the extended length?

[2002maniac]

Nice! Why the extended length?

just so I wont have to make new brake lines. If I were to make another one I would just make it out of 1/2" plate and have the master right on the firewall. it would be much less machining.

The bracket is 1/4" shorter than the stock booster and the master is moved 1.25" upward to allow a straight shot for the pushrod from the relocated pickup point on the pedal.

[Mike B.]

Actually, if you move the m/c up one inch (along with the pickup point on the pedal) the pedal ratio goes from 4:1 to 6:1.

6:1 is just about perfect for a manual setup.

[2002maniac]

Actually, if you move the m/c up one inch (along with the pickup point on the pedal) the pedal ratio goes from 4:1 to 6:1.

6:1 is just about perfect for a manual setup.

mine's actually about 7.25:1

I think I'll try a smaller than stock porsche master cyl if it will push enough fluid. That should also help with pedal effort.

[Mike B.]

You should have no issues with pedal effort on the stock M/C with a 6:1 or greater pedal ratio.

[Massive Lee]

Interesting discussion.

1:6 pedal ratio on a stock MC. Is "stock" the 21mm 325 master or the 23,8mm M3?

Mike, what MC will you run on your M3 with front 4 pots?

Lee

[Mike B.]

Lee,

Take a look at this link - http://www.stoptech.com/tech_info/Pe...ster-Guide.pdf

It provides a lot of info on setting up a manual system.

I'll be using dual 3/4th (19mm) masters with your 13" rotor 4 pot (1.63" piston) fronts and E30M3 rears. My calculations (along with input from a Tilton engineer) show that I shouldn't even need a bias valve with this setup.

[2002maniac]

Interesting discussion.

1:6 pedal ratio on a stock MC. Is "stock" the 21mm 325 master or the 23,8mm M3?

Mike, what MC will you run on your M3 with front 4 pots?

Lee

The ratio will stay the same regardless of MC used. What the pedal ratio measures is how far you have to move the pedal to move the master cylinder. The higher ratio the greater mechanical advantage you have, however, a higher ratio also means longer pedal travel.

[Mike B.]

Update:

I am now making pedal clusters with dual masters (or triple w/ clutch) that allow for balance control via cable. It will incorporate most aftermarket M/C's (Tilton, Wilwood, AP, or Girling)

[FredK]

Hm. So the brake MCs sit inside the cabin, then are plumbed through the firewall, just like the clutch MC?

[PiercedE30]

Very nice. How much?

[Mike B.]

Hm. So the brake MCs sit inside the cabin, then are plumbed through the firewall, just like the clutch MC?

The masters still mount in the engine bay. An additional hole(s) will have to be drilled. I have a template to make things easy for the installer.