The very first step in balanced braking would be to use the SAME brand and grade pads on both ends. This is the same logic that dictates four identical tires for proper handling. Proportioning valves were used years ago in cars with rear drum brakes because of their self-energizing property and tendency to lock under high loads, especially during nose dive. Most 4 wheel disc cars don't use it and ABS makes it an unneeded complication.

If the car is truly diving more than it should, start with ride height. If the nose is low, the front springs are weak. If it's correct, front struts may not be damping and need replacement.

I had bad nose dive on my '93 945T. New front springs (about $40 each @ FCP Groton) did a magnificent job correcting it. If you can reduce the dive, it will go a long way toward "equalizing" the front/rear brake bias.

Good luck.

Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

I am not sure about this. But, I think there is a part in your brake system called a "proportioning valve". This valve adjusts the pressure applied to the front and rear brake pads. Sometimes they get stuck. They are not adjustable.