Quote Originally Posted by rspears View Post
Like Jerry says, the two are inter-related, not independent. Every pump will have a pump curve, which is where the pump performs relative to volume and pressure - increasing volume on the X axis (vertical), increasing pressure on the Y axis (horizontal) with the curve falling off from left (0 pressure, highest volume) to the right as pressure increases. The pump will have a point of maximum efficiency, but will operate anywhere on the curve - at any given pressure (system resistance) you will have a specific volume flow for that pump in new and clean condition.
Jerry,
That makes sense.My thought is volume helps crate torque because of the lower rpm range it occurs and pressure helps hp because it is ,if I am correct,helps with hp because the speed it delivers the fuel at higher rpm's where generally hp occurs.But that now doesn't make sense because as you say,the volume is somewhat a constant threw up the RPM range.True enough that hp is a derivative of torque.

The CPI systems uses pressure in the range of 58 to 65 PSI with GPH in the range of 50GPH.

Now this isn't just a exercise in mental questions.The Astro CPI in tank pumps do have a limited life expectancy.We have found a good priced in-line pump that has more than enough pressure,but is 10 GPH less than the spec of the O.E.M. in tank pump.I was wondering what effect it would have??.And how that would effect a V8 swap in the Astro vans using a SBC 350 or 383.