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Author Topic:   Brake Bias gauges and bias knob adjuster
Rat Trap
Dirt Maniac

Total posts: 129
posted February 28, 2005 08:03 AM  
We are switching over to the wilwood brake bias knob adjuster and bias gauges set up this year. How exactly do you hook these up? The knob has one in and one out. The gauges each have what appear to be one in and a bleeder valve.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 28, 2005 08:20 AM  
Rat, if the bias knob is being used as a right front brake control, it should be inline with the right front brake line. The gauges just need to be teed off front and rear lines. I put my pressure guages before the shut off valve in order to limit the affects of the valve on pressure readings. Try to mount the gauges so the bleeds are higher than the master cylinders, if possible, in order to help with getting the air out. Hope that helps.

Rat Trap
Dirt Maniac

Total posts: 129
posted February 28, 2005 02:38 PM  
I'm assuming the knob is to be used to adjust the rear (more rear on tacky less rear dry slick). Would this be correct way to go. Out of front master make a tee one side going to gauge the other side going to the front brakes. Out of the rear master go to knob control, out of knob control to gauge out of gauge make a tee to go to each rear wheels?

wfoondirt
Dirt Forum Champ
Total posts: 505
posted February 28, 2005 03:00 PM  
Do you not have a balance bar on the pedal assembly? That is the correct way to adjust front to rear bias.

I am assuming the prop valve you have now looks something like this

If so that isn't what you want to use for a right front shut off. I use one like this

It is much faster to adjust. Or you can use a regular high pressure ball valve on the right front.

Reguardless unless your rules don't allow aftermarket master cylinders you should use dual m/c with a balance bar to adjust front to rear bias.


Here are a couple pictures of a complete setup.

High res versions:
http://wfoondirt.com/upload/P3133563.JPG
http://wfoondirt.com/upload/P3133564.JPG
http://wfoondirt.com/upload/P3133562.JPG

[This message has been edited by wfoondirt (edited February 28, 2005).]

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 28, 2005 03:03 PM  
I've never used an inline valve to adjust for rear brakes, but instead used the balance bar adjuster that changes the balance between the two master cylinders. The way you described would work for the gauges except that you would tee to the rear gauge, not go in and out of it.

And you are right on more rear brake for tacky and less for dry slick. It helps turn (or not turn) the car.

Rat Trap
Dirt Maniac

Total posts: 129
posted February 28, 2005 03:33 PM  
We are running dual m/c. Our rules don't allow for a shut off on the right front. Only front to rear adjustment. The knob style is what we have not the lever style. The car use to have the hand crank type adjuster but we took it out for this year, we could never tell that it made a difference whether it was cranked one way or another. We were thinking we would be able to adjust in the pits at the m/c how much the front m/c would go. Then on the track we could adjust the rear with the bias knob as the condition of the track requires, but of course the front would always remain the same. Are we thinking the correct way here?

Desert mod, your correct about teeing to the rear gauge and not in and out of it. thanks


Desert Mod
Dirt Full Roller

Total posts: 60
posted February 28, 2005 03:55 PM  
Well, I've never done that but I guess it would work. I'd rather figure out why the balance bar didn't work. Believe me, you can tell the difference between all the way one way and all the way the other. Could be your bias adjuster has a problem, which could be causing you other braking problems. Besides, you get more adjustment if you are changing percentage rather than eliminating percentage, which you are proposing to do. If you keep the same on the front and eliminate some of the rear, your total braking decreases.

Istock66
unregistered Total posts: 60
posted February 28, 2005 04:40 PM           send a private message to Desert Mod   Edit/Delete Message   Reply w/QuoteBBBBBB
I mounted my gauges low, not high.

Low you can just open the bleeders and let gravity do the job, just make sure your bleeders are pointing up.

If you mount it high you must bleed it by pushing on the pedal and pushing the air out.

I would fix your bias at the masters, and not use the aftermarket inline proportioning valve. its not needed if the bias on your pedals work.

Rat Trap
Dirt Maniac

Total posts: 129
posted February 28, 2005 04:43 PM  
yes i think we did have a problem with the balance bar, but we couldn't see anything wrong with it. Which was one of the main reasons for switching, but we didn't realize the bias knob work the way it does. We thought it would adjust front to rear pressure just like the balance bar did. We have redesigned the entire **** pit and its kinda too late now to go back to the bar. We also bought all new wheel cyclinders and pads also to eliminate all possible problems that we may of had last year.
Can you tell me what the pressure is on the front with the balance bar turned all one way and the pressure if its turned all the other way?

Rat Trap
Dirt Maniac

Total posts: 129
posted February 28, 2005 07:54 PM  
Ok i went to Wilwoods website. This is what it says about the valve i have and gives instructions to hooking it up. Basically i will go from the rear m/c to the valve, out the valve to the rear wheels, with a tee somewhere in between to my gauge. I do believe this is different from how most everyone else runs, but it should work. Thanks for your suggestions and for the pictures.

WILWOOD PROPORITONING VALVES FEATURES:
Compact and lightweight forged billet aluminum construction has made Wilwood's proportioning valves the best available. Pressure adjustments range from 100-1000 PSI and provide for a maximum decrease of 57% in line pressure. This adjustment lets you fine tune the front to rear braking balance by proportionately decreasing the rear (or in some cases the front) brake line pressure.


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