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Replace 460LPH Walbro with?

RB26, maxed out the 460LPH Walbro at around 500rwhp on e85. They are rated to about 600hp (assuming flywheel so seems about right). 

Want something in tank and looked at this: http://walbrofuelpumps.com/walbro-485lph-fuel-pump-high-pressure-tia485-2-f90000274-universal-e85-ethanol-ti-automotive.html

Given the car has -9s and is almost done as far as turbos go, I only need enough to stop it leaning out and run a touch more boost. 

Does that pump really support another 150hp? Are there better in tank options available? 

Given I already have it in there, wiring would be direct swap over it looks like. 

Yes I have the pump direct fed from battery (with relay triggered by standard fuel pump wiring).  

Thanks all :)

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Looking at other threads on here, people saying these can support 450rwkw? 

Has been suggested that I remove this pressure valve and bump base fuel pressure to 3.5. Any issues with that? 

Would be great to not have to get into the tank again though..

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Good to know. Seems others are making up to 450rwkw with these pumps and I found reference on here to that inline valve causing tuning issues for someone else before. 

Will start by removing that, might be a cheap fix yet :)

Haven't removed to inspect yet. 

Did the same setup in the Silvia without issue. 

Have run direct feed to battery via relay, relay is trigger by standard fuel pump relay trigger. All with suitable gauge wiring. 

I have a 34 with this pump.

You are running into issues on E85 like every other 34 owner I presume. Now, everyone I've seen this issue with has a GTT, but I wouldnt be super suprised if its the same thing at play here.

The fuel filter is your restriction. It always seems to happen at about 350-375kw on E85.

Also, there's two types of the Walbro 460. One has a 70psi internal relief valve, the newer one has 120psi internal relief valve. This means that at certain amounts of boost the earlier one is going to pump back into the tank as opposed to into the rail. When you consider 45psi is base pressure, 70psi gives you 25psi of boost before you start to run into issues.

Change the filter and the pump (if need be, do filter first) and problem will be magically solved.

You can try running without the filter on the dyno to confirm.

genuine Nissan for sure, $45 from Nissan IIRC and I'd assume cheaper from Justjap, Kudos etc...

2 hours ago, ActionDan said:

Fuel filter huh... 

It's new, but just a generic one. It has been about 1000ks on e85 now, I wonder if it's full of gunk?

Best option for replacement? 

 

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Edited by mr_rbman
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I think the solution might be to put 2 filters in parallel.  the problem not necessarily being that the single filter is a bit blocked/dirty, just that the single filter is inherently a restriction when trying to shove that much E85 through it!

If you can make it work with 2x filters in parallel, then it might be worth considering a less bodgy solution which is one of those massive fuel filters that use screw on cartridges like an oil filter.

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Run a second braided fuel line. In theory a single 8mm fuel line will support around 600hp or slightly above that with 98, throw in E85 and your engines demanding 30% more fuel. I run twin Walbro 255 with dual feed to the factory RB26 rail and that should in theory be good for almost 1000hp. (Rail and 8mm return line being the next restrictions).

In saying all that though, I have seen Walbro 460s run over 400kw so a change of filter is your cheapest best option currently.

I'm pretty sure other people are making more power without any of that stuff around. 

I'll remove the damper in the tank, put a fresh filter on (as it's done 1000k's on e85 now so worth changing for safety I hear) and see where that gets us. 

 

 

If you are replacing the filter don't put an OEM one back in, especially with E85. I had an issue with my GTR a couple of weeks ago, the solution was a high flow speedflow filter, fixed my issues 100%.

Damper was removed a while ago from memory. 

Mines a 40 micron -6 fitting speedflow filter, was $100 according to my invoice, my mechanic just got it for me.

I was having a few teething issues when running E85, slight hesitation at around 3800-4000 RPM under high boost, and the occasional knock light coming on. Wasn't happy with it so i took it to a different shop, he took one look at my filter and wen't "that thar is your problem". Changed the filter over and under load i gained 5psi rail pressure, car feels heaps different. Like i was actually shocked how much smoother it was...

Hmm OK, I'm in two minds about the filter as plenty of others seem to make bigger power with the standard filter in place. 

Would have been good to know if just a new standard filter would have solved your issue. 

I don't think it's the case of the filter being clogged so much, as much as what GTSBoy said, the actual filter itself is restrictive and it can't flow that much fuel in it.


I was also using a ryco filter. I now use an Earls filter, but as I've backed down my power goal I now run two filters because the Earls filter I have is 30 micron and apparently 20 is what you want (the ryco one is 20 I read somewhere).

This is likely why the best option is to run them in parallel when chasing that much power. Earls have a 10 micron filter for their big filter, but I found any time I swapped between E85 and 98, in either direction, the filter would near-instantly get clogged with a 10.

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