Hi Rex, I have two Holley 130gph pumps mounted inside the fuel tank with inlet socks on them. The two run on independent electrical circuits but the lines join into a single -10 outside the tank. The external filter was 26 micron. It was a now discontinued Holley filter that looks like an Oberg UFO. I didn't check the flow limitation of that filter, which was my mistake, and there is no direct info on it now, but the Oberg version is limited to around 90 or so gph. I was normally just turning on one pump for piddling around but then turning on both for the full passes. With both pumps on, the filter just couldn't flow so it was overworking the pumps. Now installing an inline Holley filter rated at 260gph.
This issue also set me to doing some hand calcs to verify my fuel system was otherwise up to the task. I went and checked the fuel pump ratings again, which advertise at 130gph, but are really only 88gph at 60psi or100gph at 43psi. Under boost then and using rough calcs, 88gph x 2 pumps = 176gph. At .6 BSFC, it takes 175gph to feed 1800hp, which is about all I am going to use for now. Also it takes 135 lb/hr injectors. I have Holley 160lb/hr injectors so I'm ok there. And the fuel pump/filter, lines are all now ok to that level as well. As a side note, we used this same engine/turbo/fuel injector combination in a previous car and it started running out of injector (maxed out duty cycle) by around 25lb boost level, which should be about 2100hp or so. I need to get comfy with the car at speed for a while and see what it can do at this power level, so I'm not going to be turning it up that high.
Yes, I'm referencing the manifold pressure. It was all working correctly on the dyno and through the first few runs, but then the logs show fuel pressure was climbing, as it is supposed to, but then would start dropping under higher boost/load/rpm, indicating fuel starvation. Fortunately I was on C16 so nothing got hurt, but it was up around 14:1 at points.