V8 Brake swap for UrQ - saga continues..

[Mark Rosenkrantz]

Ben,

Without doing the calculations, I suspect you have a swept area problem.
Going to "bigger brakes" often leaves a long pedal.

When doing brake modifications, the size of the new caliper pistons have to
be taken into account when choosing a brake master cylinder.  With no other
changes, when increasing piston size, often the result is a master cylinder
primary piston which will sweep right past the correct operating area and
either bottom out on the secondary piston, allow cross circuit
hydraulics, etc.  I'm tired... hardly the right term but I just got home
after frostbiting the J-24 all day.

Brakes are too often thought of as individual pieces and not as a system.
Big mistake.  Brembo, Stoptech, etc.... they're not taking a single caliper
and making different brackets.  The caliper bodies might be the same across
different applications, but the piston bores sizing is application specific
for, bias, area and to minimize pad taper.  Take for example a Stoptech
application for a 2000 A4 bodied car.  All use the same caliper body, but
the piston size and radio is different for a 1.8T, a 2.8, and the S4 to
match the spring rates (for bias) and master cylinder volume.

A couple of remedies:  A proportioning valve might be enough.  Properly
sizing the master cylinder.  Sleeving the calipers with smaller bore
pistons.

Good luck,
Mark Rosenkrantz