The Fuel Pump Thread

[Marko R1]

I'm using the wrong terminology...it's not dropping in pressure but rather he cannot increase the fuel pressure relative to boost level 

[GTRNUR]

That can only mean you have not got enough fuel flow.  Either due to a pinched pickup, or inadequate supply line from the tank.

With regards to wiring, I always recommend overkill with the size of the wiring, especially inside the tank.  I'm using 34amp Teflon coated wiring to my twin in-tank walbro 460's. No issues at all.

Note: That is assuming your not trying to run more base pressure than say 43psi and no more than 30psi, so not more than 75-80psi at the pump.

Edited July 30, 2016 by GTRNUR

[Marko R1]

I'm using the standard fuel line from boot to rail. I did the same in my previous gtr with rb30 so that will be fine.

I did notice today when I changed the fuel filter under bonnet that the rubber line connecting to the underside of the filter was oversized for the standard hard line under the car...it actually felt loose-ish. That could be the culprit

How did you run the 34amp thru the top hat? Not sure if I use the existing Anderson plug as I don't want to modify the top hat.

[WARLORD]

i have a Holly dominator 1800 which is e85 compatible unlike some of the dominator pumps and it has 2  walbro pumps in side so how high of a failure are people having with walbro in general as it looks like a much used pump for e85.

On 5/23/2016 at 7:56 AM, The Mafia said:

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

 

[WantGTR]

3 hours ago, Marko R1 said:

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.

 

I used 8 gauge up to the top hat. I did tidy up the wiring from the pump to the top hat. I didnt upgrade the wiring there. I figure walbro thought their wiring is up to the task...

[GTRNUR]

15 hours ago, Marko R1 said:

How did you run the 34amp thru the top hat? Not sure if I use the existing Anderson plug as I don't want to modify the top hat.

I have a PHR aftermarket top hat with a huge connector on it that allows running of two pairs of 34 amp wiring to the pumps.  But if you want to keep a standard hat you can just drill and bolt some stainless steel M6 bolts through the OEM hat. Then run your electrical connections to that.  EFI Hardware sell these with plastic insulators and rubber seals if you have to mount on a metal hat (like an R32).

Edited July 31, 2016 by GTRNUR

[Marko R1]

12 hours ago, WantGTR said:

I used 8 gauge up to the top hat. I did tidy up the wiring from the pump to the top hat. I didnt upgrade the wiring there. I figure walbro thought their wiring is up to the task...

I had similar thoughts...the supplied walbro harness should be up for the task

Edited July 31, 2016 by Marko R1

[Marko R1]

20 hours ago, WantGTR said:

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

 

Where did you measure the voltage, from the top hat or are the fuel pump with the pump out of the tank? What u did obviously worked

How much power is your donk making?

[WantGTR]

18 minutes ago, Marko R1 said:

Where did you measure the voltage, from the top hat or are the fuel pump with the pump out of the tank? What u did obviously worked

How much power is your donk making?

Both times i measured it was at plug which connects to the top hat.

Pump was in the tank, all connected up and car was idling away.

Not sure but still standard ecu and injectors...

[Marko R1]

Thanks all for the feedback...it is very much appreciated and takes out a lot of the guess work

[discopotato03]

Seems the Walbro 460 E85 pump is the go , has anyone used one in an R33/34 GTR with the hose down to the strainer . I ask because my 33 has a GTR pump and bracket in the tank . Probably should have kept the original GTS25T bracket which puts the pump at the bottom of the tank .

Scotty have PM'd you for a kit to fit one of these pumps , I asked your preferred method of getting larger wiring into the tank . Those bulkhead pins shown above look interesting and I think EFI something or other do something similar . Also can you supply a reliable high current relay .

Thanks in advance cheers A .

BTW have search my ass off recently about pumps and wiring .

 

[Dose Pipe Sutututu]

submerge it... or if you're not chasing massive numbers not ramming loads of boost into the motor (thus increasing fuel pressure) I suggest getting a DW300 version 2. They drain less current, fits on the OEM GTSt cradle without needing metal hose clamps and produce much less heat.

[GTRNUR]

3 hours ago, discopotato03 said:

Seems the Walbro 460 E85 pump is the go , has anyone used one in an R33/34 GTR with the hose down to the strainer . I ask because my 33 has a GTR pump and bracket in the tank . Probably should have kept the original GTS25T bracket which puts the pump at the bottom of the tank .

Scotty have PM'd you for a kit to fit one of these pumps , I asked your preferred method of getting larger wiring into the tank . Those bulkhead pins shown above look interesting and I think EFI something or other do something similar . Also can you supply a reliable high current relay .

Thanks in advance cheers A .

BTW have search my ass off recently about pumps and wiring .

 

I'm using two 460's in an R34 GTR.  I've mounted one at the bottom where the strainer is and the other inside a PVC container where the OEM pump normally is. 

The container has a hose going through the bottom down to a second OEM pickup mounted next to the primary pump.

I run a T piece on the return with a venturi on one side to retain the venturi pump, and the other side of the T goes to a hose that returns to the upper mounted pump container.  This ensures the upper pump is always submerged such that it can prime and pull fuel from the bottom of the tank.

Works flawlessly.

Both pumps run all the time ensuring they are primed and also not stalled,  I use PWM speed control on the pumps, referencing injector pulse width so its adaptive for 98 or E85.

[lcxu105]

Ok this is my fuel system. Walbro 460 e85 pump -6 lines 1000cc injectors on a rb30 25 neo. Gtx3582r with .82 rear. 

Hoping to make 550rwhp. Or 420rwkw on either pump98 or e85. Starting to lean towards e85.

Can anyone see a problem with this setup.

[The Mafia]

13 minutes ago, lcxu105 said:

Ok this is my fuel system. Walbro 460 e85 pump -6 lines 1000cc injectors on a rb30 25 neo. Gtx3582r with .82 rear. 

Hoping to make 550rwhp. Or 420rwkw on either pump98 or e85. Starting to lean towards e85.

Can anyone see a problem with this setup.

On E85 yes. The pump won't flow enough or be near it's limit, and the injectors will be almost maxed.

[lcxu105]

30 minutes ago, The Mafia said:

On E85 yes. The pump won't flow enough or be near it's limit, and the injectors will be almost maxed.

Pump will or won't be. Just trying to understand what you wrote. I know that the injectors will be near maxed.

[The Mafia]

You should never tune beyond 80% injector duty cycle. Same goes for the fuel pump - it should have about 20% headroom too.

You won't have any of this headroom trying to make that much power with those parts.

[33SOM]

Just purchased a 6466 for my built rb26. Looking at around 7-750rwhp on e85.

Currently I have a Walbro 460 and a Turbosmart fpr1200.

Does using my current 460 as a lift pump into a SPR400 with twin 460's inside the tank seem overkill?

Can anyone recommend me anything else?

Cheers!

[Piggaz]

3 minutes ago, 33SOM said:

Just purchased a 6466 for my built rb26. Looking at around 7-750rwhp on e85.

Currently I have a Walbro 460 and a Turbosmart fpr1200.

Does using my current 460 as a lift pump into a SPR400 with twin 460's inside the tank seem overkill?

Can anyone recommend me anything else?

Cheers!

It seems so long as you run the correct line size, it will work without issue.

Intune (I am in the process) has just installed the 1200 version using two 460's (with the option of 3 if needed).

It's quiet and did the job without fuss. -10 lines were run everywhere. AI suggest a minimum of -8 overflow to not pressurise the surge tank. That will require modification to the fuel hat. 

[33SOM]

5 minutes ago, Piggaz said:

It seems so long as you run the correct line size, it will work without issue.

Intune (I am in the process) has just installed the 1200 version using two 460's (with the option of 3 if needed).

It's quiet and did the job without fuss. -10 lines were run everywhere. AI suggest a minimum of -8 overflow to not pressurise the surge tank. That will require modification to the fuel hat. 

Awesome. Was just about to ask about line sizes