Injector Confusion

[John_Calabrese at ENGELHARD.COM]

Be careful, a rising rate regulator is just a vacuum reference regulator, it is
not a function of RPM, but a function of manifold pressure (or wherever your
taking the vacuum signal from).  When pressure is low (vacuum), the diaphragm in
the regulator doesn't get any help from local air pressure to fight against the
fuel pressure on the other side.  The only thing fuel pressure is pushing
against is spring tension.  When pressure is high (WOT at any rpm or boost
pressure), the diaphragm has the spring pressure and the local air pressure
pushing against it, requiring a higher fuel pressure to lift the opening to the
bypass, resulting in a higher fuel pressure.  It is rpm independent.