How to get adjustable brake bias?

[Aslet]

I have a '84 944 track/autocross car. I get a lot of front brake lockup and want to add more rear brake bias. I know with the early 944's, you can not change the brake bias valve. So, what do I have to do?

I want to add the Willwood brake bias adjuster: Wilwood High-Performance Disc Brakes - Porportioning Valves

With the stock MC though, adding this will only allow me to lower the rear pressure, correct? Do I have to/can I add a 944S2 MC (that has a changable bias valve) then add this unit?

Any suggestions?

Thanks!

[KEV951]

you can put the 928 s4 valve in your master cylinder for more rear bias

[Aslet]

You can not change the valve in the 944 MCs as far as I know...

[KEV951]

i changed mine in my 86 951 , it screws into right into it.

[HondaDustR]

There's two different types of master cylinders in the 944's, Girling and Ate, which are not interchangeable. Is it possible one version allows changing the valve and the other one doesn't?

[Capt Squid]

I have not seen a factory proportioning valve on the N/A 944s.

It is unusual for a 944 to need less front braking. Usually under hard braking the rears light up. You should check the condition of your calipers before you do anything else.

If the calipers check OK, then start with your brake pads. A good number of the 944 Spec racers run Hawk blues on the front. On the rear, some run a different less aggressive pad, some of us run Hawk blues and a few run cheap pads from Pep Boys.

You can adjust the pad bearing area by either grinding off the pad corners or by cutting a slot in the pad center. At the last race, one of our group tapered the edges of his rear pads to reduce the area by around 25%. On his test run he was then locking up the fronts so he had to replace his rear pads. Make your adjustments in small increments or use junk pads for testing.

[James Chimney]

From a motor cycle back round I would add air bubbles to the rears brakes (I only used rear brake at stop lights and trail braking and did not want it to lock up) hold rear brake lever down and open bleeder release the lever then close bleeder, trial and error to get it where I wanted but once there was great had to stand on it to lock it up.
Would it work on a 944? use common sense please if you try it

[Aslet]

Adding air to the brake lines is not very good, IMO. For road and autocross it may be fine. I would never do this on the track though.

Capt Squid: Thanks for the input. About 3-4 years ago I went through the brake and added a new MC and rebuilt all the calipers. The rears may not be working well though, hence the front lock up (same front and rear pads too). Not only am I getting front lock up, it feel like they lock very easy, so maybe something is wrong.

I will give the brakes a good look over before I start adding anything. They need to be working right before I try to upgrade anything.

Anyways, I am also fighting with suspension setup issues. Its getting closer, but with ever step (as racers know) a new issue pops up.

Why must cars be so fun

[Cocacolakidd]

Bah-humbug to all those who have said that you cannot add or change a Brake Bias Valve to a 944na. It screws right in place on the driver's side front port - the port for the rear brake lines. What you do have to do is to procure a brake bias line for that area from a 86-89 turbo so it will allow the extra room there to add the bias valve (The bias valve sticks out approx. 2 1/2" from MC, and the OEM line will not fit correctly). I have added the 5|17 and the 5|33 bias valves to several NA's in the past, and that was on both the Girling and Ate MC's - all turbo and 928 bias valves will interchange size wise - just do not use the wrong a bias valve so that you loose effective rear braking.