Well the ball is rolling on the new motor and I want to make sure I've got all my ducks in a row.

The old setup was a 5.3 with MP T70, single Walbro 255 in-tank and some Siemens Deka 60#ers.... I had no fueling problems like this, but then again, I only put 6psi through that system.

The new stuff will be a forged 5.7L with WCCH stage II 317 heads, MP T70 for now and ill be breaking the motor in on the WG (same 6psi) and turning it up to 15 eventually...

I plan on keeping the same intake manifold and injectors on the new motor, and adding meth in a couple months. Will the single 255 handle that or will I need another on a hobbs switch or maybe an in-line?

I would imagine that system would be good for ~10psi on the new combo before upgrades right?

 

I've ran my 5.7 up to 12-14 lbs of boost and 6k with the same fuel system. When I ran E85, the single pump couldn't keep up when the injectors got up to about 90% DC. DC would go up, but wouldn't get any richer, I don't have a FP gauge . I'm going to add an inline I think, just so I know I can maintain pressure with at least these 60's

 

Same thing here. My 255 intank and 60# start dropping fuel pressure past ~5000 rpm. My afr hovers around 12.0 above 5300 in third gear no matter how much fuel I add with the tune on 10psi. I am still contemplating what I want to do. I have already added a hotwire kit which only marginally helped. My next options are:
-Fuel pump voltage booster (BAP, Magnavolt, MSD)
-Adding an inline (with or without hobbs switch??)
-Dual intank with either another 255 or stock fuel pump. If I use the stock pump, I dont know if I would need to use it as the primary or secondary. I am thinking secondary as it would be less catastrophic if there were a failure. If the primary fails, the truck won't run. If the secondary fails, you won't know till it is too late. I think I would rather have the larger pump as the primary for this reason alone. However, under normal driving conditions, the stock pump would be more efficient and wouldn't recirculate as much fuel as the 255 keeping the fuel cooler.

 

I think heating the fuel is something that you don't have to worry about until you get a big pump.

 

I don't planning on messing with the E85 stuff with this one... Just regular 93 pump gas and the occasional splash of 110 at the track.

I guess ill run it and see and just watch the FP guage, if need be, ill just add an in-line. Bu even that won't be until the higher boost levels... 10+

 

Get a second pump and don't worry about it.

 

As much work your gonna have to do. Pullin the bed off, hackin up the bucket to fit both pumps, wiring,etc. Midols well buy another walbro255 and use it as your secondary. There only $100 for the pump,sock, and harness. Then that way you wont run into a problem of the used stock pump failing on you. Just my two cents

 

i'd plan on another pump if i were you. im running out of pump(walbro 255) with H/C/5.3 with a 76mm turbo as soon as it hits 10psi half throttle

 

I would put an inline on it.

 

Yeah, ill throw an inline 255 on it just to be safe, ill be running it rich too for a while, so I'm sure ill need more fuel anyway.