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Walbro 400Lph Problem

Hadouken

By Hadouken,
in Engines & Forced Induction

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XKLABA
XKLABA

Don't flatter your self about the non return valve idea, we have been using them for more then 20years in the race cars My brothers car, I don't have a pic of mine in my phone It runs a VQ35HR wi

scotty nm35
scotty nm35

Because it is perfect, for me and my setup. I guess you just don't appreciate the hard work I put into it, designing a failsafe system on my own, using a single reg and return when everyone on here wa

Ben C34
Ben C34

To seperate the banks and use one reg wouldn't it go Pump > rail> non return > tee piece to common reg on both sides? Pretty easy.

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SiR_RB Grand Master

SiR_RB

Posted
Posted

I may have made a mistake, my pump kit came with a black rubber sock/sleeve that goes over the pump for when it's mounted externally to stop vibrations etc while clamped down....

I put that around the body of the pump submerged in the tank in ethanol....I'm going to check it this avo I have a feeling it's starting to perish and block the intake sock on the pump lol

  • 1 year later...
The Mafia Grand Master

The Mafia

Posted
Posted

Sorry about the thread revival guys, but I am at a moot point regarding fuel pumps and it is driving me mad.

What I plan on doing is running a pump on its own (With the intentions of it becoming a lift pump once I need more fuel).

I have a brand new Nismo 275lph @ 80psi pump sitting in a box wrapped in plastic. I've been told not to use it for E85, and I want to use E85. People have told me to get a Walbro 400lph pump which is E85 compatible. So I did some homework:

The walbro 400lph isn't exactly that. (I have attached flow diagrams)

It flows 315lph at 70psi (45psi base, 25psi of boost)

Nismo flows 275lph @ 80 psi which I estimate to be over 300lph at 70psi.

Anyway - should I just drop the Nismo in and run E85 through it and be done with it?

I love Nismo pumps. So quiet, small, and, its Nismo!

post-7271-0-88763900-1407373396_thumb.jpg

scotty nm35 Grand Master

scotty nm35

Posted
Posted

The ethanol version of the Walbro is absolutely silent, quieter than the Nismo/Tomei pumps. It uses a turbine vane, not an oil pump style gear type of old.

If you want ethanol compatibility there is only one choice, that said, you may get many years out of the Nismo. Personally I would sell the Nismo off and buy the 460 Walbro, and pocket the change.

The Mafia Grand Master

The Mafia

Posted
Posted

Mr Mafia is that the R33 GTR or GTS25T Nismo pump ?

Personally I think an EFI pump that draws 18-20 amps on its own is hardly current tech electrics . I think the GTR Nismo is advertised as drawing 8 or 9 .

A .

R34 GTR Nismo pump Disco stu :)

If it's a 8-9 amp pump, what does this mean for me?

And works with the factory fpcm, but I don't think Mafia needs that. :P

haha actually... yes I do. I am running a Nistune (R32 GTR ECU in my R34 GTR). Works really well.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

R34 GTR Nismo pump Disco stu :)

If it's a 8-9 amp pump, what does this mean for me?

haha actually... yes I do. I am running a Nistune (R32 GTR ECU in my R34 GTR). Works really well.

Have you, or are you planning to direct wire the pump through a relay? The stock wiring won't support the Walbro.

discopotato03 Grand Master

discopotato03

Posted
Posted

Twice the current draw from a battery that's sometimes not real close to the alternator .

I haven't looked that closely into the fuel pump control modules , basically they are like a ballast resistor with a fancy relay to bypass it when the computer says so . With GTRs the FPCM has two stages or resistors and the usual bypass . Nissans like the Q45 V8s in the US use the same type of thing and at one of their sites they have pics of them opened up and in various stages of melt down - literally .

Their purpose was to minimise the amount of fuel doing circuits at low revs and loads and to shut the pump up to a degree .

The upshot is that the standard wiring won't appreciate more than double the fuel pumps normal current draw which is why the bolt in Nismo pump works with the standard system .

One feller many years ago reckoned an easy way is to leave the std or similar pump in tank and run an external pump to do the hard stuff . A standardish pump should easily cope feeding into the external because its not creating the rails pressure head on its own . . And its not like either pump can run away speed wise because all the fuel is going to the same place . External pumps make the wiring easy because there's no fuel tank to feed/seal wires into . Bonus is they're easy to change if you mount them in an accessible place .

In a way running pumps in circuit is like running several in tank because logically the fuel all goes to the same place . The difference is that running them in series rather than parallel means they share the work load and if primary isn't a gorilla pump it doesn't matter . If the external tries to pump more than the in tank its flow increases because the effective pressure ahead is less .

A .

scotty nm35 Grand Master

scotty nm35

Posted
Posted

which is why the bolt in Nismo pump works with the standard system .

No, the Nismo works on the stock system because it is designed to run on low voltage, and not draw too much current for the stock wiring when doing so. Try running a Walbro 255 on stock cruise voltages and you will find it doesn't last very long.

Personally I run twin 255's for that very reason, more flow for less current, but they are not ethanol rated. These days I would be dropping an e85 460 in, as I am doing to my evo this week.

Running the stock pump with an inline after it is a good idea, but you would need to match the sizes of the pumps. No way a little 20 year old oem stock pump will flow enough to keep up with a decent inline, and that would cause all sorts of problems.

  • 4 weeks later...
boostn0199 Grand Master

boostn0199

Posted
Posted

lol so I am still confused. Should I just use the Nismo for my intank pump for E85, and then upgrade to a surge tank when I need more and then use the nismo as a lift pump?

Thats what I did had the nismo initially and then it became my lift pump when I went surge so far 4 years on e85 and no problem.

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