Wilwood knob style adj prop valve install

[8AV8]

Anybody ever installed a Wilwood knob type adj prop valve to have more control over line pressure to the rears?

Please share experiences.

 

[boostingbuick]

I have. It takes alot of work to install this. You need to remove the fatory p-valve and run the front brakes straight to the brake master cylinder. The rears will have this valve in it. I would not use this to crank up the pressure to the rears for launching. To hard to get it back where it was. But if you have rear disc brakes it will give you great control.

 

[8AV8]

Why not use this to increase rear pressure for launching?

 

[toofastforyou]

I have one mounted like "boostingbuick" said...I'm not using it anymore since I have a trans brake. I had it installed back when I had no trans brake. I was looking for some ways to get the brakes to hold the car at the line...But it was not as effective as I thought it would be and in the end, I got tired and had the trans brake intalled. So my word is this: If you're looking to get more boost at the line, passup on the prop valve and get an electric trans brake! (but not a stage-right pos!)

Claude

 

[8AV8]

I have one mounted like "boostingbuick" said...I'm not using it anymore since I have a trans brake. I had it installed back when I had no trans brake. I was looking for some ways to get the brakes to hold the car at the line...But it was not as effective as I thought it would be and in the end, I got tired and had the trans brake intalled. So my word is this: If you're looking to get more boost at the line, passup on the prop valve and get an electric trans brake! (but not a stage-right pos!)

Claude

I'm not ready for a tbrake yet. Did the prop valve help at all?. A friend that has used one suggested it to me. He said it helped him.

I did a search on this and couldn't find anything.

 

[toofastforyou]

Frankly, I never was able to find a setting that helped me launch the car better...:frown: It's still on the car, but I'll remove it someday and reinstall the original prop valve...

Claude :redface:

 

[novaderrik]

how does an adjustable brake proportioning valve INCREASE rear brake pressure?
it works exactly the opposite of that- it is like your fuel pressure regulator. turn the knob out, and it allows the full brake pressure that the master cylinder is putting out to get to the rear brakes. turn it in, and it decreses the amount of pressure that gets to the rear brakes. but, just like your fuel regulator, it can only put out as much pressure as is going into it. it isn't a pressure multiplier.
it can be installed after the stock prop valve- but it will only help if your rear brakes are locking up under hard braking. it allows you to turn it down a bit so all 4 wheels are stopping the car instead of the rear just sliding along.
i had one in my Nova, and it really helped a lot in keeping the stock rear drum brakes from locking up when the C4 Vette front brakes grabbed and shifted the weight forward and unloaded the rear tires. with it all the way open, the rear brakes would lock up almost instantly and the car would get all slideways. after fiddling with it a bit, the car would just squat down and STOP. and this was without a manual configuration without a brake booster of any kind.
so, to summarize, and adjust able prop vavle will do NOTHING to help a turbo Buick hold boost a the line, but it will help it stop safe and straight at the end of the track once it is properly adjusted.

 

[Louie L.]

Remove the factory prop valve. Then install the aftermarket unit in line with the rear brakes. This is the only way to control the full MC pressure to the rear brakes. Most cars have issues with the factory prop valve anyways, so overall brake feel improves.

At the race track you will use more rear brake bias to help hold boost. Dial it down for the street.

 

[boostingbuick]

The factory valve limits the pressure to the rears. But the fronts have no limit. This keeps the rears from locking up and causing the car to spin. I like to have the rears lock up just after the front. The car has a great feel and only use the adjustable for stopping. I would go for a Transbrake and start out with a soft launch. You don't need to find the sky with it. Plus it will help you get that rear suspension hookin. I don't use it all the time, but when I need its there.

 

[84BuickGNYorkPA]

Remove the factory prop valve. Then install the aftermarket unit in line with the rear brakes. This is the only way to control the full MC pressure to the rear brakes. Most cars have issues with the factory prop valve anyways, so overall brake feel improves.

I believe that this is the answer for anyone having issues with the rear wheels locking up before the front ones. Also why replace the factory valve when a adjustable is much better.

Chuck