By "brake bias" do you mean a proportioning valve?

If so, I do not.
In theory, 4 wheel disc systems should have all 4 calipers and rotors sized in a 2 to 1 ratio with the front having twice the braking force as the rear.
My front calipers have 2 pistons, the rear calipers have 1. The front rotors are 13", the rears are 11.7".


Some well intentioned people have suggested the use of a proportioning valve but I don't think that they fully grasp the issue here. A prop valve does not increase pressure, it only reduces it within the line in which it is installed. If I can't skid now, I won't be able to skid with even less pressure to the brakes.
My situation comes down to insufficient force at the calipers. The booster is either too small for the job or it has a leak, not allowing it to reach it's potential.