PRESSURE B     [c force  with pressures]     P.c - P.r = c force
P.r is the pressure variable in c force. P.r is determined by the stiffness of the main comp stack.  A stiffer comp stack will produce LOWER P.r, resulting in a greater pressure drop and higher c force. Consider P.r as a primary pressure which is regulated by mv shim stack and P.c as secondary.  'c force' comes from P.c - P.r. If P.c increases from a stiffer cadj, P.r increases as well.  See example to right.