I'm currently upgrading to rear disc brakes and the car has had no proportioning valve for years running a 15/16 bore Chrysler style master. I'm doing so due to the fact that I've been killing Wilwood rotors on the front after only a few events and always using the last turnouts at the tracks I attend. I'm putting a valve on the line going to the front brakes (race car only). In searching around on this there seems to be quite a difference in opinion on it's location.... Noted a few of the brake parts manufacturers recommend this. Thoughts?

I mounted my adjustable prop valve on the firewall, worked just fine. Although in an effort to clean my firewall up I'm moving it to the rear just before hose that connect the brakes from body to axle.

Proportioner goes in the front system. Large rear drag tires will over come skinny fronts. When I first used Will Woods in 93 we wiped a pair of rotors in one season. It was the pad material. That 2nd pair of rotors were good until 2016. Two different cars, same set of rotors transfered to a faster car.
Doug

Baer sells a master cylinder with the ability to mount a prop valve to the bottom of it. So in their mind it doesn't seem you can get to close to the master, they seem to know what they are doing.

I have 4 wheel Disc Wilwoods. Adjustable Prop valve on rear brakes. Set it to the middle of adjustment when I installed it years ago and have never touched it. Lots of street miles and plenty of track passes.....never a stopping issue. Brake pads look great and no abnormal wear, front or rear. The idea for rear adjustable was to have front brakes with full load from master and dial up or down the rears as needed, depending on stopping quality.

Here is the Baer master cylinder with prop valve that I'm using on my Duster project.

Never used one, never had to. Use the correct MC with the correct bore size and the bias built in, and plumbed correctly according to your combination (tire sizes, caliper sizes) and it just always works. If you use any old auto parts store master and don't know the bias, it's trial and error.

That would make for a very nice clean set up. I too just converted to wilwood discs on front and rear after 30 yrs with stock fronts and wilwood rears.

I will have to see if I need to change out my old master cylinder. If so this may be an option.

Trying to attach pic...

I mounted the proportioning valve in the rear circuit. I put some rivnuts into the subframe connector and mounted the valve so that the adjustment knob just pokes through the floor between my knees when I'm driving. And I found a rubber grommet with an ID the size of the top of the prop valve housing. I slid that into the floor sheet metal and then slid the prop valve into the ID and then bolted it to the subframe connector. I'm not sure if it is really watertight since the car never sees the rain.

baer sells this bracket.

Mine

That’s basically what I’m doing Doug.... and it will be on the front brakes.
Jay

My street car is set up like DVW is, easy to reach
BTW, don't forget to remove the residual valve from the M.C.

Jay, I'm mounting mine between the front hoop bar and the kick panel. I've moved all my lines from the engine compartment to under the dash area. Let me know if you want a picture.

DVW, Why does the valve have a front and rear in port and 2 - front and 1-rear out port?

Can, why remove the residual valve?

I have wilwood 2 psi res. Valves installed, as I have wilwood disc brakes installed
Mark

Valve has 1 in then 1 out going to the line lock. Line lock has 1 in, 2 out with 1 of them plugged as the front line T is further down.
Doug

you may want to call wildwood and check what friction rate the pads are or should be. I bought a 4 wheel disc brake kit from them a few years ago and it was eating the rear rotors, they had sent the wrong friction rate pads, changed the pads and all was good.

I do proportion valve on front brakes and line lock on rear brakes. This way I match front brake power to equal the rear with bigger tires and the line lock I hit the button 1st, hit the brakes 2nd then only the front brakes will clamp on. This I feel allows a safer burnout as I can control roll out with my brakes and not just expect to roll or possibly launch forward as soon as I let go of the line lock button.