914 Brake Bias?? Yeah or Neh?

RonD922 · 04-21-2002, 08:23 AM

Hello,

I have read alot about the brake bias in the 914 and have heard a lot about taking it out completely. I am upgrading the brakes probably with 911 "S" calipers in the front and my 914 front calipers on the rear, so what I was wondering is should I just take out the bias valve, or try to get a more modern adjustable valve, or leave it in?

Thanks,
Ron

PS this car will be AutoX maybe Drivers Ed. I am 18 and want the car very tight! I have a 2.7 RS motor to put in, but I might find that motor to much for the car!!

Anyway I interested in strictly performace not comfort!

Joe Bob · Joe Bob's Garage

It depends on if the rear brakes lock up before the fronts......that's what the proportioning valve tries to prevent.....

Rear wheel lock is a bad thing....makes your car want to swap ends in a rapid manner.....

Test it out in a dry parking lot. You can always add an aftermarket adjustable one. About 100 bucks....

Dave Bell · 04-22-2002, 07:15 PM

Collection of advice I got from others......

Stock proportioning valve is nothing more than a big spring that your leg is compressing.

Normally you can hear a faint click in the factory proportioning
valve at the knee of the pressure curve. You can change the knee of the curve by adjusting the set screw in the valve. The set
screw is pretty short which limits the range of adjustment. You can remove the factory set screw and replaced it with a longer bolt and turn it in so far that you never get to the knee, never proportion.....

Total cost.... a new metric bolt.

Another alternative is to remove the prop valve and put in a VW brake line T.... about $5 new or $0.50 from a junk yard.

I have done both of these mods on different cars.

- Dave

John Rogers · 04-23-2002, 11:47 AM

For a track car or one that is driven at driving events regulary I'd say to put in a tee. The brake pedal will be much firmer and you will get a little more use from the rear calipers. I have BMW brakes on both ends of my race car and a 23mm M/C and I have found that if I want to lock up the wheels, all 4 lock at the same time. Since I have a 4 cylinder and you have a 6, you have more weight on the rear so you would have a harder time to lock up the rear calipers. Good luck.