Rear Bias plugs or bias valve.

[adidas_kn]

Before I go through with my SHObros order I want to know if there is anywhere to get a pair of these small little guys to plug the brake porportioning valve. $40 for a pair of tiny plugs gets me. I've been torn on this for almost 3-4 years now. There has got to be a cheaper solution. Trust me I love what the boys at SHObros are doing for our community but I just can't get past that price. They look like $2 plugs for some kind of plumber thing.????? Anywho. Anybody else know where to get these things from?

I was also wondering if something like a Wilwood brake Bais valve that is adjustable would be easy to adapt? My buddy got one for is 80' Trans Am and it is a simple 2 in 2 out with a bracket and a **** for front to rear bias. Ford motorsport makes one too.

 

[Phoenix]

SHONUT has these too, Never seen this anywhere else. I'm not even sure if it's street "legal".

 

[DemonNeno]

I was also wondering if something like a Wilwood brake Bais valve that is adjustable would be easy to adapt? My buddy got one for is 80' Trans Am and it is a simple 2 in 2 out with a bracket and a **** for front to rear bias. Ford motorsport makes one too.

I was planning on using something like this for the rears right at the firewall. I don't see why this wouldn't work if you can run 2 seperate lines through and back out. Everyone seems to beat around the bush when it comes to proportioning valves.

What always got me about the bias valve is that when it cuts the rears out and loads the fronts harder, it makes the car nose dive even worse. Running a fixed pressure through to the rears would be better than that stupid valve. Maintaining adjusted pressure for the rears sounds like the idea ford should've stuck with from the get-go!

 

[adidas_kn]

Should still be able to leave the Bias valve out back in the same spot the old one was but just roll up under it if the bias needs changed. I think once you find an acceptable bias for street and light tracking it should be okay. They also sell a remote cable to adjust the ****.

 

[Racer X]

I was planning on using something like this for the rears right at the firewall. I don't see why this wouldn't work if you can run 2 seperate lines through and back out. Everyone seems to beat around the bush when it comes to proportioning valves.

What always got me about the bias plug is that when it cuts the rears out and loads the fronts harder, it makes the car nose dive even worse. Running a fixed pressure through to the rears would be better than that stupid plug. Maintaining adjusted pressure for the rears sounds like the idea ford should've stuck with from the get-go!

But... I was under the impression that the bias plugs allowed full pressure to the rears.

 

[SHO92]

The bias plugs are custom machined, they aren't just NPT plugs from the hardware store. I believe the reason they need to be custom made is mainly because of the O-ring locations and also because the thread is a hard to find metric size.

The replacement bias valve has been discussed before, but only done once as far as I know. In order to do it properly(as in 1 valve to control both sides, because 2 valves will never be adjusted equally) you need to replumb the entire brake system. The problem with that is that in a master cylinder failure situation, you'd either have just front brakes, or just rears. The stock arrangment makes it so that you'd have one of each.

Btw, my sig pic is from 2 days at the track last spring, running bias plugs. The fronts obviously still do most of the braking.

 

[1993MTXSHO]

if you went to the rear and tied the rear arm thing down so the car never knew when the rear of the car lifted would that kinda do the same thing as bias plugs? Seems like thad be a good way to save the 40 bucks.

 

[Call_Me_crazy]

I to could not stomach the price for those plugs, I simply removed & disassembled the existing valves(easy to do) then threaded the inside iameter with a tap to except a standard 10mm headed bolt. To complete the assembly i used a small washer & some thread lock on the bolt and after tighting the bolt i filled the rest of the valve with urethane sealent inorder to make absolutly sure they would not leak. I have yet to reinstall and test them because my car is simply not ready to be back on the road , but i am 95% sure i wont have a problem with the way they have been modified and they will install the same way they came out.

 

[shomesomesho]

Actually you can just take the stock bias plugs and grind down the sides of the little movable cylinder with the holes in it, and that will increase flow. The more material you take off, the more flow. Just take off a little at a time, but not so much that the rears lock up before the fronts. It takes some experimentation. Even just grinding off 1/16" of material will dramatically increase the flow to the rear brakes (and cause premature lock up), so I try never to go beyond that.

 

[adidas_kn]

if you went to the rear and tied the rear arm thing down so the car never knew when the rear of the car lifted would that kinda do the same thing as bias plugs? Seems like thad be a good way to save the 40 bucks.

Yeah I was thinking something like that. The rear is already adjustable but even when fully activated it doesn't give the rears enough pressure. So if you did like shomesomesho said "take the stock bias plugs and grind down the sides of the little movable cylinder with the holes in it" and making the rear adjuster arm a ratchet type unit it could be adjustable. You know like being able to lock it in a different position to increase flow and so forth.

Maybe?

 

[1993MTXSHO]

maybe im way off here but on all abs cars as long as your abs works, have a lot of flow to the rear wont matter because the abs wont let it lock up.

 

[luigisho]

I would sadly ask you to search on this one.
Only because GaryM had some posts and maybe a pic or two of his setup with the Wilwood (or similar) adjustable bias valves that you might find interesting.

 

[DemonNeno]

But... I was under the impression that the bias plugs allowed full pressure to the rears.

Yes, they do. However, it's not adjustable rear pressure. Non-abs cars + full rear pressure = bad. An ABS car with adjustable rears would also benefit from not depending on the ABS to keep it under control.

EDIT: fixed my mix up in my first post.