ratt_finkel

I am ditching my ABS. And am setting up a manual brake bias adjuster. From what I understand, I need one with 2 Inlets and 4 Outlets. I've searched this forum to the beginning of time and looked all over the web. I'm at a loss finding one that is appropriate for my application.

Help!

Jeremy Foley

63Corvette

Hi Jeremy,
Normally, on a "real race car" a manual brake balance adjustment is accomplished by dual master cylinders with a balance bar between them for front/rear adjustment. Normally you would buy the entire assembley from an aftermarket manufacturer like Tilton or Lakewood.

SouthernSon

You might call Randy at DRM:

http://dougrippie.com/products/drm-c...ster-cylinder/

ratt_finkel

That just seems like a lot. What does everyone else do? Run the stock proportioning bias? I understand it's somewhat rear biased. Which doesn't bother me. But I am worried about braking in more than just a straight line.

I came across this in my searching. Sounds like he doesn't recommend this with stock calipers and even then only for the right set up.

redtopz

All you need is a wildwood rear prop valve for the line going from the master to the rear abs inlet. Works great.

JVetthead

installing this setup on my car right now. I run stock front calipers in rear and just went to the big AP calipers in front. This master provides more volume for all them extra pistons.. and the proportioning valve just limits pressure to the rear,one inlet from master-one outlet to rear brakes.

moespeeds

I also looked into this a few years ago. I concluded that a proper 2 M/C setup with pedals was the best solution, but it's a royal PIA to switch over. I don't see why what Redtopz is saying won't work, you just have to adjust the bias under the hood, no big deal. I've got a buddy who runs a Mustang who uses that setup.

SouthernSon

When referencing upgraded package, it is assumed more/and or bigger pistons requiring more fluid volume to counteract longer brake pedal. Personally, I like for the pedal to remain as high as possible for blip/brake performance. The stock M/C with SL6 calipers still goes a little long for my tastes.

ratt_finkel

Correct.

I don't mind a mushy pedal. What I like are brakes that are easy to modulate, with good feel. Don't really want to leg press every time I step on the brakes either.

SouthernSon

Well, there is that to some degree.

Beatnik

Dual master cylinders are really the only way to get real front-to-rear proportioning. If you want to change the knee point for the rear, that can be done with a "proportioning" valve.

You can kill multiple birds with one stone by doing this. On both boosted cars, and race cars, the vacuum signal is often irregular and interferes with the driver's expectations of the brakes. By removing the booster and going with a pair of non-boosted master cylinders you get your choice of cylinder size (pedal hardness) and proportioning while eliminating the uncertainty of the booster.

We did the pedals and masters on Brianne's car. It was easier than you might think. We plated the firewall where the master cylinders came through and built a bracket to hold the pedals in the stock location using the stock pickup points.

Modified firewall


Bracket for pedals

ratt_finkel

Thanks Jason. I just don't think we have time for all that right now. We are already way behind.

Beatnik

I think you are nuts for trying to finish this and compete this year. I swore I wouldn't bring another car out there unless it was running and driving in February and we had time to sort it, and then tune it (both chassis and engine) before heading to Colorado.

I'm worried that something will pop up during testing, you'll do a makeshift repair (again) and not finish the event (again).

ratt_finkel

Jason, I appreciate your concern. Maybe you want to have this conversation in a more private setting?