Hi all,

I'm just weighing up my options for altering the brake bias on my old Mercedes track car.
It locks up the rear wheels most of the time.

My options, from what I can see are, using a bias valve in the rear brake pipe and keep the original servo master cylinder, or slightly modify a BMW e30 twin master cylinder adjustable bias pedal box and lose the servo assist.

What do you guys think?

If you've got any other suggestions, please feel free to comment.

Cheers Frank.

Depends a lot on what the bias is to start with, a valve will only work if you are over braked on rear.

Apart from the rear locking up, the brakes are spot on.
I've uprated every corner with bigger grooved discs all round, ebc yellow stuff pads, braided hoses, and race spec fluid.

If it wasn't for the rear locking up, the brakes would be perfect.
At Cadwell on Friday, I was out for 25-40 minutes every time with no worries about the brakes.

[Edited on 16/11/14 by fha772]

I don't see why you can't put a bias valve into the rear line as you suggest, for simplicity

Keep it simple, bias valve

I'm leaning towards a bias valve, but I just wondered if it was the best option.
I'm not too fussed about the work or cost, just what is the best option with regards to performance.

Just 1 more question...

If I go with a bias valve, do I go for a screw, or lever type?

Screw

More adjustable and less likely to be knocked/moved.

What you want is one of those set ups they used to have in rally cars with two separate brake pedals (Though I believe the front one overlapped the rear one so it was just rear or all) though I imagine you'd need some serious skills to be able to operate two completely separate ones (Not to mention another leg).