[twiceblown]

okay, Chris, so with the #s you supplied for flapper and diaphragm area, i come up with:

flapper diameter / diaphragm diam / Flap Area / Diaphragm Area / Stock Actuator Spring Pressure / Turbine Housing PSI / Flap PSI / Diap PSI / Ideal Actuator Spring Pressure

34.00 57.00 1.41 3.96 7.00 30.00 42.23 27.70 10.67
38.00 57.00 1.76 3.96 7.00 30.00 52.76 27.70 13.33

For the two sized flappers assuming that there's a 7psi spring in there, Chris should upgrade the spring rate to 10.67PSI and Brian should upgrade to 13.33PSI for ideal considitions (equilibrium between intake manifold pressure * diaphragm area vs. flapper area * turbine pressure). NOTE: this is assumed to be with the same setup as FWombat.

Anyone have the sizes of the flapper and diameter of diaphragm of the TD04 stuff? I'm curious for what i need. I know 9# springs are much better than stock 6#ers, but i'd dying to know what would be ideal.
Damon