Actually stock pressure to a CP3 in a Dodge is 8 PSI.
Pressure itself is not an indicator that a pump can supply fuel to an engine...its the ability to maintain pressure....and that is where volume comes in. Pressure comes from the measurement of resistance of flow (Volume). SO pressure and volume are inversely related. Meaning when one goes up, the other goes down. SO if you reduce pressure on a system, and you have a 150 GPH pump, you have more potential flow at lower pressure to help maintain a level PSI than at higher pressure.
OK….say you had a 100 GPH pump.
At 0 PSI…it put out 100 GPH. Then if you increase the pressure to say 50 PSI…your GPH at that pressure reduces to say 65 GPH. SO if you ran the pump at 50 PSI…and the engine usage encroached on that 65 GPH flow rate…it would reflect in a pressure drop. This due the potential flow is greater at lower pressure. This is all assuming you had adequate flow on the suction side of the pump and the gauge was reading correctly….2 HUGE issues we deal with on a regular basis.
Hope that was as clear as mud……
SO more or less….yes…150 GPH pump @ 8 PSI should be more than enough for twin CP3’s. Remember, with duel CP3’s, you are doing the same thing we are doing to the engine feed. Supplying WAY more volume needed to maintain pressure. You double the volume to the “Common Rail” and boom….pressure stays up and you can run larger demand items with out pressure drop. BUT Pressure in an injection system is slightly different as they need pressure for atomization and to cram a predetermined amt of fuel though tinny orifices in a certain amt of time. Hence the super high pressures. Our side is not that critical. More or less a CP3 just needs a certain amt of positive pressure and its happy. (Positive pressure means it has more fuel it can handle and not in a need)
Ok....coffee time......