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Two Stock Lift Pumps

Woody35

Woody35

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What are your thought about adding a second stock lift pump inline with the other one already there. My uncle works at the parts store so i can get them pretty cheap. I already got the FTB
 
It would certainly help. Although if paying a good amount of money I would invest in one walbro and put it in with the existing working stock LP. If youre getting it at cost then its probably half the price of a Walbro though.
 
I run parallel lifts; Heath h/o & walbro, 99% of time the Heath pulls the required fuel when running empty, when towing heavy I energize the walbro & shut off the Heath, when racing or climbing hill with heavy load I energize both, series is okay but I prefer parallel with my FTB you move more fuel volume over psi is what is needed IMO
 
i dont really tow very heavy and I can get a pump for 45 bucks so im think im just going to throw it on there. i was looking at the walbros and heath's lift pump but i dont see a huge advantage when i can get a stock one cheap. if i didnt have a discount i would probably get a walbro though.
 
I now run both of mine off of an independent relay that is controlled by the power that would have gone to the single lift pump if plugged in,

2 relays and control coil (very low current draw on OPS/PCM) of each has it's own toggle switch & 12V LED; LED monitors power out of the relay to lift not the control coil input in my pillar post so I know if I have power to which pump or both if I am running both.
 
Thank you for the info. I think im just going to run both at all times. just got to figure out what i want to tap into for power and where to mount the pump. im thinking right before stock lp location with cutting the hard line and replacing with the regular stuff.
 
Woody, do you have a fuel pressure gauge? If not, definitely add one.

I'm not sure I see the reason for the 2 pumps inline. If you have enough fuel pressure, no need for a 2nd pump. If you don't, I'd rather see one capable pump than 2 inline. TD's setup in parallel makes more sense if you need that kind of fuel flow, at least you get the volume benefit of the 2 pumps, not sure you will with them inline. Just my thoughts, I haven't tried it.
 
I dont think there really is any difference if you run them parallel or series. Flow has to do with pressure and volume/area, so if you have one line going to the filter at the same pressure you got the same flow. You benefit either way. Just like there is no such thing as more flow at lower pressure, unless something like a large temperature difference is taken into account. with today's power capabilities and larger turbos and higher RPMs having them both can help keep the IP happy.
 
FWIW many pumps put out more GPM/LPM @ LOWER PSI ergo they would not sell/rate as such, IE Walbro & Delphi pumps rated 7psi & 45gph, and GM lift 28gph at same psi.

Back in my USN days multiple pumps on ships our fire pumps were 1750gpm rated @ 150 psi, seawater service pump 3000gpm @ 70 psi, physically smaller/larger pumps so yes you can have a difference of psi over gpm/gph and vice versa.

Now parallel vs series not sure one over the other makes a difference, with exception since GM pumps are self regulating my thoughts were that the 2 pumps would not be working as efficiently in series as they might be cycling off/on more than if they were in parallel with separate switches to secure them when not needed,.

Plus the outlet valve of the GM pumps if plumbed in series would both wear at same rate as both would have constant flow across the "innards" of the pumps.

My setup in parallel allows for redundancy in event 1 pump gets weak or inoperative I switch on the offline pump to take over, in series with both pumping both are on same duty cycle, in shipboard systems where I learned how systems are built pumps are often built with redundant parallel capability in mind.

As to flow vs psi with me opening for full FTB is have larger lines to be filled than the OEM set up so recovery when WOT or heavy load demand requires a larger gph pump capability, (2) 28 gph pumps in parallel by math is more than a single 45gph pump, but in series the flow restrictions internal to the pump themselves may negate some of total delivered volume.

With my setup (1) 45 gph parallel with a 28 gph neither pump impedes the flow of the other limit to the flow is how much fuel the IP is "gulping up", a single Raptor significantly more flow potential than my setup, but Raptor cost and all eggs in 1 basket /pump are not my desire.

Is my setup the best, maybe/maybe not but it works well for me since installing nearly 4 yeas ago.
 
With your parallel feed, did you need check valves so that when only 1 pump is on it doesn't feed back to the tank? Or does the pump itself act as a check valve?
 
I understand where your coming from but the simplicity and the somewhat more flow you get even if it isnt as much as the pump is capable of because the way its put in is still enough for me to get a benefit from my run of the mill tune coupled with ftb
 
Woody I guess the answer you are looking for is yes, 2 might do a better job than 1. I'm not convinced you need 2, but the redundancy is certainly worth the 45 bucks even if you don't see a difference from the fuel flow. I don't think you answered earlier, do you have a fuel pressure gauge?
 
Dave01 said:
With your parallel feed, did you need check valves so that when only 1 pump is on it doesn't feed back to the tank? Or does the pump itself act as a check valve?
Click to expand...

Thought of that aspect when I 1st was doing it, checks down that small were hard to find and ones I did find were expensive; but both pumps outlet have a rubber valve sort of like a heart valve work as a check.

Since both pumps have same PSI ratings the valves can survive the pressure from the other, plus by running just 1 or other unless towing heavy or racing where I am using all the fuel capacity from both with hard engine load/work I am not over supplying/pressurizing against the offline pump as I'm always using some of the output of a pump or pumps when running the engine.
 
sorry i didnt answer i do not. but when i floor the truck at a complete stop there is a slight delay like the turbo stopped spooling for a milisecond then all hell breaks loose and i think that is from not having enough fuel pressure to support the ip's demands. nothing like that when i roll into it
 
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