Sump or Not

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
1,872
15
38
Neenah, Wisconsin
just saying, the lift needed to reach the filters/Pump is the same for both and vertical runs are almost negligible when it comes to pressure or vacuum needed to move the fuel for priming

I don't want anyone else reading this thread thinking that somehow the weight of the fuel in the tank is going to create pressure to help prime with a sump when it wont. that's all
Correct.
 

gmduramax

Shits broke
Jun 12, 2008
3,595
4
38
Nor cal
usually the pumps inlet is mid tankish. either way, im agree with you as once the fuel is below the pump inlet, its no longer gravity fed.

its really a mute point for the fass, airdog, and fuel lab. they have no issues under a draw situation. the Kennedy's and other fuel pumps like it (holley and so on) CAN have issues drawing "uphill" so to speak as they are not really designed for it.

the only time i worry about a sump, pump design and line routing is in a race application. You have much more freedom to setup the system to work 100% correct since your constraints change IE: could use a different chassis, fuel tank/cell, pump location, line location, no bed, and so on.

again, this "benefit" is extremely minor since the fass, airdog, and fuel lab all have the ability to use the stock pick up (no cutting or dropping of the tank) and will supply enough fuel for 1k hp.

Any lift pump that returns fuel should not use the factory pick up. Either modify it or put on a sump. Even if you’re holding rail pressure, even if you’re making 500hp. The factory pick up is too small.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
17,149
24
38
Phoenix Az
Any lift pump that returns fuel should not use the factory pick up. Either modify it or put on a sump. Even if you’re holding rail pressure, even though if you’re making 500hp. The factory pick up is too small.
i disagree. if you are not dropping pressure because you are not using more volume than the stock pick up can provide, the stock pickup is fine and quite a few guys have shown that to true to the HP as i stated.
 

gmduramax

Shits broke
Jun 12, 2008
3,595
4
38
Nor cal
i disagree. if you are not dropping pressure because you are not using more volume than the stock pick up can provide, the stock pickup is fine and quite a few guys have shown that to true to the HP as i stated.
I picked up 4mph from modifying the factory pickup. My truck held rail pressure just fine. LMM’s pickup is 5/16’s. LML’s pick up should be modified even stock power. I tested it by measuring lift pump pressure at the port past the factory filter.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
17,149
24
38
Phoenix Az
I picked up 4mph from modifying the factory pickup. My truck held rail pressure just fine. LMM’s pickup is 5/16’s. LML’s pick up should be modified even stock power. I tested it by measuring lift pump pressure at the port past the factory filter.
then it wasnt just the pick up that netted you the high mph if you are holding rail just fine. the LMM's ive replaced were the same as the previous years. that was a 2010 and a 2008. Regardless, the OP has a LBZ. Thats what i am giving information towards, not all vehicles.
 

TROJAN366

Gold Rush
Jan 13, 2012
2,490
0
0
MASS
Late to the party but my truck has been running an AD165 with a PPE pickup and it maintains positive supply pressure with an LBZ pump+10mm stroker and 200s.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,413
2
38
Minnesota
I had the Fuelab 200 on my pull truck with a bypass regulator and never had any issue keeping up to 2 10mm pumps and 150 injectors. Fuelab's also have brushless motors, so less parts to wear out. My current truck has twin Kennedy pumps on it right now, but I will be replacing them with a Fuelab this winter.

Greystonelbz send me a PM and I can recommend a good shop in MN...
 

graystonelbz

New member
Jul 19, 2007
293
0
0
Prior Lake,MN
I had the Fuelab 200 on my pull truck with a bypass regulator and never had any issue keeping up to 2 10mm pumps and 150 injectors. Fuelab's also have brushless motors, so less parts to wear out. My current truck has twin Kennedy pumps on it right now, but I will be replacing them with a Fuelab this winter.

Greystonelbz send me a PM and I can recommend a good shop in MN...
pm sent
 

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