Skyline Fuel Pump

[stranger12]

Skyline Fuel Pump

Hi Guys,

 

I have been spending sometime looking at the fuel pump and options available for my r34 gtt.

It seems that walbro 250Lph is the best choice as it is a straight swap but only good for 500 bhp. I can only imagine that is 500 Bhp at flywheel.

 

I am looking to get 500+ hp on flywheel so that is too close to its maximum. Next level up is 450 litter however confused on what re wiring is needed .

Can anyone briefly explain what is needed to install it ? I have also seen people having issues as soon as they have 3/4 of their tank empty because the fuel pump is not fully submerged. Does this impact r34 gtt?

 

thanks

 

[Dose Pipe Sutututu]

• stainless hose clamp
• horn relay
• a few terminals
• 8ga power wiring
• an 8ga fuse holder

and no, those issues are from shit installs... I run mine till the light goes on before it starts missing/surging on the track

[colourclassic]

This thread has comprehensive details of the procedure for running direct battery voltage to your pump:

The pump must be mounted in the cradle at the same level as the factory pump, with the fuel strainer pointing forward IIRC. I have no issues with surge or starvation even below 1/4 tank. 

[stranger12]

many thanks, I will read the post.

so in essence you run a direct feed from battery ? if yes I guess that needs a relay to some ignition or something as else the battery will die in few mins when you switch the car off.

 

also if I go overkill and get a fuel pump that is 450 lph which is rated for 750bhp and all I have is 300bhp, does the pump get hot or knackers the pressure regulator?

 

Would you guys have a catch tank?

[GTSBoy]

"Direct feed from the battery" completely implies "through a fuse and a relay".  And the trigger to make the relay come on is the original fuel pump power from the ECU/relay.

Too much pump won't knacker your FPR, but it may circulate fuel too fast, which leads to too much heating - both from passing too much through the engine bay/rail back into the tank and simply because the fuel pump itself beats the fuel up as it goes through.

A Bosch 040, 044, Walbro 255, etc etc is fine for PULP at the sort of power level you're talking about and even to higher power levels.  A bigger pump is not a bad idea, but there's really no need to go for a ~450 l/h pump.

 

You could/should do some searching on these forums, because all these questions HAVE BEEN ASKED BEFORE.

 

And when you say "catch tank" do you mean "surge tank"?  I take it that we're still talking about fuel systems and haven't taken a left turn into oil control?

[stranger12]

Thanks, I means surge tank:) it was late night in the uk

I am still researching to find the right item

would  a heated fuel cause explosion ?

[GTSBoy]

No explosion.  Just reduced fuel density and more prone to knock.

[stranger12]

and potentially blowing engine , I am now tempted to get 250lph as I was going to get 450 so save me from constant changing of pumps

 

is there a fuel cooler or something that I can fit with 450 if I decided to get 450?

[GTSBoy]

Pretty much any heat exchanger with a line size to suit your fuel line size can be plumbed into the return line to cool fuel back down.  Again, this is a topic that has had extensive coverage here.

[stranger12]

man thanks, I was thinking rather than over complicating things and spending too much in a hope that one day I might go above 500 , I stay with walbro 255.

 

The 500 hp quoted, is that at wheel or flywheel?

Most surge tanks I have seen have two pumps of 044 . I won't be buying this as it is cheap chinese but would you install a surge tank ?

Does it help for street use? If you have two pumps in the surge tank but one in the tank how does that help?

 

http://www.ebay.co.uk/itm/3L-High-Flow-Fuel-Swirl-Surge-Pot-Tank-2PCS-External-044-Dual-Fuel-Pump-BK-/152139356808?hash=item236c365a88:g:BCwAAOSwM4xXaPnt

[GTSBoy]

Seriously, don't go there (the twin pump surge tank thing).  A big-arse fuel system needs to be designed to suit a purpose, not thrown together from what's available on ebay.

 

These high pressure EFI pumps are centrifugal devices.  This means that as the back pressure goes up, their throughput goes down.  So when you're running them against a few bar of pressure regulated restriction at the fuel rail, they don't flow as much as they do wide open.  Therefore you will usually only need a single lift pump to feed a surge tank that has 2 big pumps drawing on it.

But I stress again, these systems need to be thought through.  Do you want to contemplate what happens when 1 of 2 parallel pumps dies?  Hint, it's not as good as when a single pump of the same capacity as the 2 pumps dies.

[Dose Pipe Sutututu]

get a DW300 pump, earth off the power i.e. bypass the FPCM... call it a day.

You're overthinking something so simple for your shit box.

Yes all skylines are shit boxes, I said it lol

[stranger12]

3 hours ago, GTSBoy said:

Seriously, don't go there (the twin pump surge tank thing).  A big-arse fuel system needs to be designed to suit a purpose, not thrown together from what's available on ebay.

 

These high pressure EFI pumps are centrifugal devices.  This means that as the back pressure goes up, their throughput goes down.  So when you're running them against a few bar of pressure regulated restriction at the fuel rail, they don't flow as much as they do wide open.  Therefore you will usually only need a single lift pump to feed a surge tank that has 2 big pumps drawing on it.

But I stress again, these systems need to be thought through.  Do you want to contemplate what happens when 1 of 2 parallel pumps dies?  Hint, it's not as good as when a single pump of the same capacity as the 2 pumps dies.

thanks, I am just curius and been researching on the net that is all.

 

SO what happens if one dies, car switches off? Would you get a surge tank ? I think it might be overkill for road and occasional track use.

 

I am still not clear if walbro is 500 at flywheel or wheel. regarding the dw300, are they a straight swap?

 

It is slightly higher than 255 but not 450 so should give me a strong pressure I guess. it seems expensive compared to walbro though

 

http://www.turbozentrum.de/luft-und-benzin/einspritzduesen/mazda/deatschwerks-kraftstoffpumpe-dw300-nissan-skyline/a-33315/

[GTSBoy]

6 hours ago, stranger12 said:

SO what happens if one dies, car switches off? Would you get a surge tank ? I think it might be overkill for road and occasional track use.

 

 

No, if one dies, your engine suffers a huge lean out and you kill it horribly.  And no, I would not install a surge tank for a street car, and I would not install one for an occasional track car unless it was suffering fuel related (ie surge) problems whilst at the track.

 

Just buy the bloody Walbro and finish this already!

[Dose Pipe Sutututu]

Walbro 450 he will then start a new thread about wiring melting and or blowing fuses. 

DW300 v2 uses less current, good for beginners.

[stranger12]

look at it this way, I am searching and sometime may not see the information so open a thread

if you keep pointing me to what might have been discussed three years ago and I can't find it then what is a point of this forum ?

you might as well lockall new threads and refer people to what is already on here.

I am not asking people to do the research for me, I do it and they ask questions if I have any .

so talking sensibly there is nothing wrong with me being curious and asking questions. if that annoys you then feel free to ignore the post.

now back to the point, I have seen people quoting they have achieved 500 whp on Walbro 250 and with dual setup 1000 hp.

Does anyone know what gurantees that fuel pump will not spark when inside the tank or what saftey mechanisms are built into it to stop this?

[Dose Pipe Sutututu]

Even if it did, even if there was a flame (not possible) there's no way the fuel will ignite because the mixtures are too rich to ignite. 

This is why electrical connectors happily live exposed inside a fuel tank.

Not to mention a fuel tank is nearly sealed so the chances of enough air getting in to enable the right condition for fuel ignition is nearly impossible.

Btw. You don't need 2 pumps for the power you're aiming for. You don't even need a Walbro 460L.

[stranger12]

yes I am going with walbro 250. I am just curious and want to know what I am buying and why

[KiwiRS4T]

Search using Google and all will be revealed. If you don't get the answer you need then rephrase your question.

[tridentt150v]

Or take the plunge and ask the shop you are buying the pump from........a proper reputable shop/dealer will know the solution to your setup!!!

hell there are even a few of them in the For sale section that have their own forum, ask ye and the truth shall be heard!!!