Walbro 255

[The Mafia]

ok bright spark - why buy a 42psi pump that is going to max out straight away?

Why not be smart and get a 275lph @ 70psi pump and have peice of mind that the pump isn't going beyond its intended purpose?

[govich]

ok bright spark - why buy a 42psi pump that is going to max out straight away?

Why not be smart and get a 275lph @ 70psi pump and have peice of mind that the pump isn't going beyond its intended purpose?

You buy the pump after looking at whether it's suitable for your application. If you only need 158lph at your desired boost level, the walbro can supply 204lph and the nismo can supply 300lph, why would you take the nismo at 3 times the price?

[The Mafia]

because the $200 255lph walboro is a 42psi pump is intended for NA applications....

So you want to put a NA fuel pump that can only handle low pressure into your turbo charged car?

A HP version of the Walboro is around the $280 - $300 mark, and is 255lph. AND you need to modify the f**k out of everything to get it to fit, and its even more of a pain in the ass when it doesn't touch the bottom of the tank.

The Nismo from Greenline is $330, is 275lph at 70psi, comes on its own bracket, has its own plug, and takes about 5 minutes to install. Oh, and it touches the bottom of the tank.

Now if you're going to go to all that trouble modifying brackets, soldering plugs and being just a general stuff around, just to save probably $50, for a pump that is about half the quality.

I'd rather Spend the extra $50, get a bigger pump, one that is designed buy manufacturer themselves (Nismo is in bed with Nissan) and something that is bullet proof.

Also, if you say "well not all of us can spare $50" then why did you buy a skyline and intend on modding it?

Edited February 14, 2008 by The Mafia

[govich]

I'm not talking about the non-HP pump. I'm not even sure why that pump comes up in discussions, since it clearly was not made for turbo cars, and is marketed as being for relatively low-pressure NA applications. No-one should be putting one into a turbo skyline.

UAS in sydney sell the HP version for $240. Have you actually installed one of these? Sure the nismo is easier to install since you don't have to actually do anything, but I fitted the walbro myself and it was nowhere near the headache you're suggesting.

It's a matter of cutting the bottom plate off the stock bracket (normal wire cutters will do it), putting 2 clamps on to hold the walbro and using 2 crimp connectors to connect the wires. I'm not exaggerating how easy it was.

Also, my walbro sits lower in the tank than the stock pump.

Why do you say the walbro is lesser quality? The nismo is expensive so it must be made of unobtanium? Nismo are a bit of a jack of all trades, i'd say a manufacturer specialising in fuel pump/fuel delivery systems would have the know-how to build the highest quality pump.

Edited February 14, 2008 by govich

[silva33]

Does anyone know of a pump that is physically the same size as the Walbro but will flow more, I had no choice but to put a Walbro into my Neo Stagea as the Bosch wouldnt fit in the fuel pump housing.

[Sydneykid]

An N/A engine making 500 bhp will quite happily run at 8 psi with a carby (that's Low Pressure), and 38 psi with injectors (that's High Pressure). A turbo engine may need up to 72 psi to make its 500 bhp. So picking a fuel pump based on some non specific rating of "High Pressure" is useless if you are looking at a turbo application.

A fuel pump is simply an electric motor with a pump on the end of the output shaft. If you want more flow you use a bigger pump, if you want more pressure you use a larger electric motor. Pressure is directly related to the torque output of the electric motor, torque in an electric motor is directly proportional to the size of its rotor. There is no magic in electric motors, if you want more pressure you need a physically bigger motor.

Before I get into the graphs, it is worth mentioning that manufacturer's fuel pump ratings are usually done at 12 volts (battery voltage), whereas the running voltage (alternator ouput) is commonly 13.8 volts. Hence testing is often done at both voltages.

Keeping the above in mind, please tell me how anybody would think that the Walbro can get anywhere near the Bosch looking at the following picture;

Now take a look at the flow charts noting how the Wablro drops off in flow as the pressure rises;

Do the comparison, a STANDARD R33GTR pump flows 235 l/h at 25psi compared to 210 l/h at 25 psi for the Walbro

That's the data, you make you own judgement. In case you were still wondering what I use, the race cars all have Bosch fuel pumps and the road cars have standard GTR pumps.

Cheers

Gary

[DECIM8]

This is right in the money. Well done.

Wow, learn something new every day .. Glad I didnt make a fool of myself...

I think ill be buying HKS

Edited February 15, 2008 by DECIM8

[boosted_32]

debate closed! haha nice work sydneykid! if that doesnt answer it for everyone I dont know wot will, it answers my question thats for sure

[R338OY]

Nismo

[boosted_32]

Nismo

& Bosch

[DECIM8]

HKS is about $100 cheaper Omar, Almost same power .. So you can see why id go that.

[govich]

That's the data, you make you own judgement. In case you were still wondering what I use, the race cars all have Bosch fuel pumps and the road cars have standard GTR pumps.

Cheers

Gary

Interesting that the stock GTR pump flows more than the walbro.

This still doesn't change the fact that if you want to run sane turbos on a (street) RB25, the walbro will perform well. It will theoretically flow enough to max out 550cc/min injectors up to about 25psi boost pressure at 13.5V (from the first graph).

I really don't understand why everyone feels compelled to have fuel pumps capable of flowing 200+lph at very high boost pressures (>30psi) in their RB25-powered whatever that will never see above 16-18psi (generalising to the majority of examples here, obviously there are extreme examples that need the flow).

Maybe it's just all the engineering lectures (and experience) steering me towards picking something that suits the application rather than allows ridiculous safety margins.

PS. I disagree with your physical size comment. There is more to an electric motor than "the size of the rotor" - number of windings, magnet strength (material density) etc. I would be willing to bet that there are fuel pumps around that are physically bigger than the walbro (as it is pretty damn small) with lesser flow capabilities. Even the stock R33 GTS25t pump is noticeably bigger.

Edited February 15, 2008 by govich

[GeeTR]

Maybe it's just all the engineering lectures (and experience) steering me towards picking something that suits the application rather than allows ridiculous safety margins.

Thats right, your engineering logic has no place here. This is import tuning, you fit wot has the biggest following and the most google hits

There is more to an electric motor than "the size of the rotor" - number of windings, magnet strength (material density) etc. I would be willing to bet that there are fuel pumps around that are physically bigger than the walbro (as it is pretty damn small) with lesser flow capabilities. Even the stock R33 GTS25t pump is noticeably bigger.

But how likely are you to find a setup that is smaller and higher flowing? I'm imagining the windings of a 1000hp Paxton and it looks comparatively 45% larger for its higher flow (044 being 550-600hp'ish)

Edited February 15, 2008 by GeeTR

[govich]

Thats right, your engineering logic has no place here. This is import tuning, you fit wot has the biggest following and the most google hits

But how likely are you to find a setup that is smaller and higher flowing? I'm imagining the windings of a 1000hp Paxton and it looks comparatively 45% larger for its higher flow (044 being 550-600hp'ish)

Well i gave an example, the stock R33 GTS pump is noticeably bigger than the higher flowing walbro GSS342. Having worked at repco and seen a lot of the fuel pumps they retail for everyday cars, i have to say that a large number are about the same or slightly bigger than the walbro (and flow less - generalising here and not considering pressures - because NA falcodores and corollas don't need the flow).

I'm sure Bosch could condense their pumps into smaller packaging if they tried, with the possibility of using electromagnets etc but that's a line of thinking i'm sure noone cares about it would also hike up cost..

Edited February 15, 2008 by govich

[Turbo Dave]

After watching this thread for a lil bit I had just bought a walbro pump due to the signifigant saving, but my pride and joy is not worth risking on a maxed out fuel pump so im getting a Tomei pump instead, Will this outflow 555cc injectors @ 250rwkw?

[dangerman4]

After watching this thread for a lil bit I had just bought a walbro pump due to the signifigant saving, but my pride and joy is not worth risking on a maxed out fuel pump so im getting a Tomei pump instead, Will this outflow 555cc injectors @ 250rwkw?

550 injectors will be at approx 60% duty at 250 kws running a decent pump.

[discopotato03]

Hi all , I was at EvoM net yesterday and I noticed that David Burshur has come up with a twin drop in tank pump assembly for the Lancer Evo rev heads . I'm not 100% sure but the way he talks it sounds like his Burshur Racing has found a way to get more from those Walbro 255 pumps in turbo apps .

Do those Walbro pumps have some internal high pressure relief valve by any chance ? I suppose if they did and BR found a way to cork it it may be the cheapie option for a new pump or pumps .

Also BTW their assembly includes a spiffy right angled bulkhead fitting to get the second pumps seperate wiring through the assemblys steel lid . I'd be interested to know what it is because with that it would be easy to run a secondary pump in a Skyline . Also the system has a "Y" piece above the two pumps outlet feeding a single outlet . What they do is wire relays to bring the second pump online in times of high demand . The downside is what if the wiring/relay failed and the secondaryt didn't start ? Bang ?

I'll see Iif I can find the pic , cheers A .

[RAZOR32]

I run a Bosch 044 in my car and wouldn’t use any thing else, but I sore that the Gas Motor Sport 2JZ street car runs 4X Walbro in tank pumps and makes 847RWKW @ 40+psi.

[discopotato03]

After a bit of searching I found a couple of links to interesting pump stuff . Hope they work - links .

Firstly under this heading - What your Evo needsfor a fuel system, facts .

http://wwwforums.evolutionm.net/showthread.php?t=245064

Fuel Pump Upgrade Guide

http://mkiv.com/techarticles/fuel_pumps_test_2/index.html

Chinese Copies on E Bay .

http://www.fuel-pumps.net/walbro-forgeries.html

If these links don't work could someone more computer literate than me please help out .

Interesting reads , cheers A .

Edited February 16, 2008 by discopotato03

[aquariuz6]

Hi guys,

I was curious to know what the flow difference between the r32, 33, 34 gtr fuel pumps are.

Does anyone know?