The Fuel Pump Thread

[GTRNUR]

Simple... A small electric syphon pump. I considered going that way too until I realised a syphon works fine on a Y fitting inside the tank if your return has a high flow rate.

Any serious track car is probably running an under car surge tank too, keeps the fumes, fuel and danger out of the boot.

[Borci88]

Simple... A small electric syphon pump. I considered going that way too until I realised a syphon works fine on a Y fitting inside the tank if your return has a high flow rate.

Any serious track car is probably running an under car surge tank too, keeps the fumes, fuel and danger out of the boot.

While that's probably an easy option, the cars in question I'm talking about (4 I know of), all run the same setup and don't have a jet/syphon pump. They run twin in tank pumps with a custom top hat that has two fuel lines running all the way to the fuel rail. All have been tracked and all have gotten low tanks and zero issues with surging / running out of fuel. Does this Jet Pump really work as well as we think it does?

[33GTRV]

I have an under car surge, 2 044s at near on full snot and it returns from the surge through the factory return. This set up at 13.8v should support over 1000hp on race gas qnd come bloody close on corn juice. It is fed from the stock location pump. It works because 1000's of people before us have developed systems and they're trial and error is well documented. Don't need to reinvent the wheel.

[GTRNUR]

Does this Jet Pump really work as well as we think it does?

With an entirely in tank setup, if you try and push too much fuel through the syphon jet it will not work properly or at all.

Not to mention your fuel pressure goes out of control due to back pressure in the return line.

I'm using a pump jet on one side of a Y fitting inside the tank.

How well does it work? Well with the tank on empty and running both pumps, it was back to 1/4 after about 1-2 minutes of pump operation.

[Piggaz]

I have an under car surge, 2 044s at near on full snot and it returns from the surge through the factory return. This set up at 13.8v should support over 1000hp on race gas qnd come bloody close on corn juice. It is fed from the stock location pump. It works because 1000's of people before us have developed systems and they're trial and error is well documented. Don't need to reinvent the wheel.

One problem, the 044's don't last on E85.

[GTRNUR]

+1. First 044 failed after only 5 months.

Switched to walbro 460s.

[Marko R1]

I had the same issue which is why I'm swapping my 044 for the walbro 460

[whatsisname]

Yep another one with 044 issues running E85. Didn't fail but wasn't healthy.

[Borci88]

I'm going against the grain and saying my 044 has been running for over a year fine on E85, but how long is my piece of string I guess...

[Piggaz]

Been through 6 in total.

First failure was the primary pump got lazy. The secondary covered it when it come online. Picked it up by a fuel pressure gauge and AFR gauge.

Replaced both...

Second set,same thing.

Third set, can't really remember... But enough to crack it and throw it all in the bin.

044's DO NOT last under E85 conditions. If you don't have gauges and running them, you're asking for trouble.

[whatsisname]

Mine (044) lasted for a couple of years of occasional use before it started to show signs of problems.

[dr phil]

Had a bad issue with high fuel pressure in my gt four with a Walbro e85 pump. My factory fuel return hose had a restrictor in it (scottynm35 has seen one in a S15 before). This was an R34 RB25DE model, I now have a Stagea DET engine in it.

[iruvyouskyrine]

Have seen that before. IIRC Hanaldo (what ever happened to that guy?) had one in his R34 GT-T causing a lot of headaches for him before he finally found it.

[dr phil]

Yeah if you know what you are looking for (hard bulge in the stock rubber hose, not far from the return line damper that turns 90 deg) then it's easy to find.

[NISR32.5]

So did anyone end up using the Holley dominators?

What's the general consensus on a fuel system e85 compatible that will handle 450-500kw in a 32 Gtr. I wanna do it once and do it properly.

I've been advised to go a Holley dominator from the tuner, he said we can stage the pumps and run a sensor from the ecu to keep an eye on fuel flow. They have installed a few and he seems to like them but there is no long term usage at this stage.

The car currently has a nismo intank. Will be looking for a new pump to match with the new 1550 xpurts I will be getting.

[The Mafia]

So did anyone end up using the Holley dominators?

What's the general consensus on a fuel system e85 compatible that will handle 450-500kw in a 32 Gtr. I wanna do it once and do it properly.

I've been advised to go a Holley dominator from the tuner, he said we can stage the pumps and run a sensor from the ecu to keep an eye on fuel flow. They have installed a few and he seems to like them but there is no long term usage at this stage.

The car currently has a nismo intank. Will be looking for a new pump to match with the new 1550 xpurts I will be getting.

Stay away from the Holley dominator - They have had a high failure rate.

[NISR32.5]

Was that just a batch of them? Apparently they just have walbros inside them. Anyone pulled on apart?

[Marko R1]

Hi Guys,

I finally replaced my OEM in tank lift pump with a walbro 460ltr in tank. Quiet as a mouse

Had it on the dyno and we couldn't tune it with more than 15psi...as the boost increases and demands more fuel pressure - the fuel pressure was dropping off.

I am still running the OEM wiring harness with the added relay, however, as the pump draws up to 20amps, I was told that I need to run a thicker gauge wire direct from the battery to achieve 14v at full load.

My question is this (btw, it's an r32 gtr)...can I run the thicker gauge wire to the top of the 'top hat' on the fuel tank (i.e. direct to the Anderson plug) OR do I also need to replace the wiring between the fuel pump itself and the underside of the top hat? From memory, the underside of the top hat also runs an Anderson plug. Has anyone else running a walbro experienced similar voltage issues to myself? From memory, SIR RB runs a walbro in tank as well.

I'll also replace the fuel filter in the engine bay for piece of mind as this may be a catayst to drop in fuel pressure.

[WantGTR]

Have a 32 gtr and just replaced a walbro 255lph pump with a walbro 460. I also rewired the pump with 8 gauge wiring.

Previous pump on stock wiring was getting 8.8v on idle. New pump and rewire and now getting 13.3v at idle.

 

Walbro site has a table on voltages and lph rates. Interesting to look at. 

 

The pump shouldnt be dropping pressure. You either have a leak or a faulty fuel reg

 

[Marko R1]

Thanks for the feedback. Did you run 8 gauge to the top hat only (on top of the fuel tank) or did u go direct to the fuel pump? 

If I'm not getting the voltage I need, the fuel pressure will not be up for the task and this is what I am experiencing. My tuner is certain that this is the issue. My fuel reg was fine with my previous setup (i.e. OEM lift pump with external 044 which ran power direct from batt) so I don't think it's the fuel reg.