New Fuel System
Happy 2017 all!
Been getting a few little things done on the truck and one major fix. I was having some really bad fuel starvation issues from fuel leaving the pickup area under accel after 1/3 tank, and also draining the fuel rail after 25psi and dropping pressure running e80. I thought the 340lph pump would take it a bit further but not so much.
For starters I picked up a new hanger and sending unit from LMC since the old sending unit was gittin a little senile lol. A little bit of dremal work on the base of the hanger and cutting down the stock feed tube, the Walbro 450 fits nice and snug. I used a stainless snap-loc tie wrap to secure the base to the hanger. The outlet of this hanger matches the 3/8 outlet of the Walbro so I didn't feel the need to increase line size here. I cut the old feed tube and flared it on the hanger, then coupled it to the pump with a piece of Gates 30R10 submersible hose and stainless clamps. The use of this hose is critical if you run e70 or more! The coupler hose that came with the Aeromotive e85 pump was spongy when I removed it. The price of the shit sucks, but you will not have to worry about the corn eating it.
http://www.gates.com/products/automotive/passenger-car-and-light-truck/fuel-system/submersible-fuel-line-hose
My somewhat local Oreilys had it in stock. Napa has a version of it as well, might be cheaper.
For the 3/8 outlet to the 1/2" fuel line I am using a stainless Swagelok fitting, I adapted my -6an return line to the factory return using the same fittings used on the GM flex sensor..
http://www.speedwaymotors.com/LS1-LT1-EFI-Fuel-Line-Fitting-6-AN-Male-to-5-16-Inch-Female-Black,60380.html
To solve the fuel pickup issue.... I first went and slammed three Moscow Mules, found a good stick to bite down on to keep the shock and pain from biting my tongue off while keeping the profanities to a minimum..... and purchased a SMALL piece of Holly Hydromat.
HOle. Lee. Shit.
The clockable lock ring is a nice touch to line it up how ya want, and it just so happens that it fits the rear tank perfectly front to back! I have tested it doing boosted pulls at 1/8 to empty tank, ZERO starvation and it will suck the tank completely dry. Sticker shock has wore off a bit...
So my fuel gauge is now fixed and the 450 Walbro is quieter than the Aromotive, and is now easily feeding it to 26 psi so far with ease. Have much retuning to do though, I was running out of fuel earlier than I though and was compensating with lots of injector pulswidth. Targeting the 30's next!!