I'm working on a fuel system for a VE, it's a street/puller system. I am running close to the EFI live dmax's and p-7100 trucks. My truck is heavily modded and actually has had the entire fuel supply system modified a year back for similar problems. Full 3/8 from inside the tank to the pump, custom application cummins piston type lift pump, and big banjo bolts are not enough so it all must go. With newly found traction it will actually pull the system pressure down too low while pulling the sled. Hello again retarded timing. This truck has a SBC 3850 comp DD (solid hub) and the NV4500 with a 1.375 input. I also have traction bars, blocked rear suspension, a short 5" stack through the hood, and a weight rack. Saturday night it overpowered the track off the line in 3rd, 4 LO with aggressive 285 75 r 16's and 3.54's. So I backed down to 1st, 4 HI crawled out of the hole, and hammered it. It smoked as hard as the P7100 trucks did and surprised everyone when it came to an all 4 spinning stop at 280 feet. I thick a little more aggressive tire might have been the ticket but the increased load would have ran the fuel pressure down even faster.
Here's what I have gathered for the system so far, 5/8 ID suction tube in the tank up to bulkhead in top of sender (my own home built vulcan). I'm thinking 1/2" or maybe 5/8" for lines and hoses (but I am on the fence), Dual CAT type fuel filter/ water seperator (even have a heater!), Aeromotive 13301 boost referenced bypass regulator, 1/2 or 5/8 return line. I am also going to work a new trick near the VE, since I've never seen it done I'm going to make sure it works before any discussions involve it.
I think I might want to run 2 different fuel pumps. I initially thought about a walbro 392 standalone or as a booster to the piston pump. Trouble with that scenario, I'm afraid at 80 GPH the walbro won't make the grade when the load is high. On the other hand, if I keep the piston pump, I'll have to run the fuel line up to the piston pump, back the the filters on the frame under the drivers seat, then the walbro would be on sort of a loop off to the side there as a booster(so if it fails the engine still runs on the mechanical pump).
I then thought that all the unnecessary plumbing might not be worth it, so then scenario 2 came to mind. The walbro as a primary and then a huge competition pump for fooling around. The other "competition pump" will flow a whopping 4.4 GPM @ 20 psi however, is not rated for continuous use (gets hot) OR TRANSPORTATION USE, thus the walbro as a primary. Both pumps would run independently of each other in this system.
Then again I could run an aeromotive A1000 pump standalone, which flows a decent amount of fuel, but it might fall short, and it's pricey.
SO GUYS WHAT SHOULD I DO? 1/2 or 5/8 lines (specify return or feed), and which pump or combination of pumps. Looking forward to some input.
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