Brake Proportioning Valve Setup

[tom_sprecher]

Since my last race I have installed a lever style Tilton brake proportioning valve and do not have a clue as to how to set it up. When I get on track during test day what procedure should I use and what am I looking for in order to set up my brakes w/o ending up in the back of someone or off track?

Thanks,

[Gary L]

Depends. :)

I think most of us would want to know... did it replace another (factory) proportioning valve, or was it simply added to an exisiting factory setup? Can we assume this was added to the rear circuit to minimize or eliminate rear wheel lockup?

Er wut?

[markw]

Tilton's directions are a little confusing for the valve. I believe the RX 7 did have a valve connected to the master cylinder. I imagine you deleted the OE valve. With the car jacked up and the brakes bled, have an assistant press the brake pedal with the valve in one position. You turn the rear tire with your hands. Now have the assistant move the valve to the opposite position and repeat the test. You should be able to get an idea from repeating the test, which direction gives you "more". To say forward gives you more brake, would be confusing, because the valve handle can be clocked in any postion.

[tom_sprecher]

And the valve was put in the rear circuit.

[ddewhurst]

Tom, I presume you removed the OEM proportioning valve, if you didn't remove it before you go any further. Then as I rember there were instructions with your new valve on which direction forward or backward increases or decreases pressure to the rear brakes. I used a rotrational type proportioning valve & the above is what I did. Then I turned the valve on a test day to the minimal pressure to the rear bkakes & keep increasing the pressure untill the rearend wanted to be the leader & then I turned the pressure back 1/2 turn lower & re-tested by increasing the pedal foot pressure & aggressiveness untill the brakes were happy campers to my driving style. Do your testing on a straight section of track with no cars near you.:o

[Spinnetti]

ok, first, uncross your brake circuit if not done already (most cars hook the RF with LR and LF with RR). Put the valve in line with the single line going to the rears. Get your gas tank close to empty. On track, with the tires warmed up, do a hard stop. Rears lock up before the fronts? Set the lever one way or another until the fronts and rears lock up about the same time under full braking. thats pretty much it. Once set, you MIGHT want to give a little more rear brake with a full tank of gas, and take out a little as it gets empty. Me, I just set it with a couple gallons in the cell and call it good (haven't adjusted it in years).

lol... ddewhurst, just beat me to it :)

[Z3_GoCar]

Ditto to what DD said. keep turning a little at a time untill tail wants to pass under heavy brakes, then back off.

I put mine in when I took out the anti-lock pump last summer. Otherwise, the pump is the proprtioning valve. We've also got a single line to the rear becasue of no dynamic skid control.


James