how much power will standard sti fuel pump put out?

[whatchain]

how much power would a standard sti fuel pump put out? just wondering if i would need a bigger fuel pump before a tune.

http://www.trademe.co.nz/motors/car-parts-accessories/performance/fuel-systems/auction-531427349.htm

[funkytown]

your question doesn\'t quite make sense.

A pump will put out fuel - not power. Your fuel pump has the ability to pump fuel at given pressures to support a given HP.

However you should know the rate at which a fuel pump will deliver (known as lph) fuel will vary based on fuel pressure, LPH is inversely related to fuel pressure. That is - as fuel pressure increased the pump is not able to pump as many LPH there for your horsepower potential actually drops. There are lots of graphs showing this on the intanetz.

Why this is all important is because you have not described what fuel pressure regs you are running in the aim to acheive a given base pressure. At that point consult said intanetz graphs for comparisons on LPH and rail pressure .

There are then some clever calculations on said intanetz to convert what a pump is able to sustain in actual LPH to hp.

The stupid answer is: I personally run factory rail base pressure, and just a Walbro intank and it manages 300wkw.. ;D Its righhht on its limits though and have just upgraded. (they are rated at 500 or 550hp from memory)

Also - factory pumps are known to die later in life.. its a REAL cheap EASY upgrade for piece of mind and able to support plenty of HP for the average Joe doing the walbro upgrade.

[whatchain]

lol sorry that was a bad way to put it. what i meant to say was how much lph does a factory pump put out?just want to know if a standard fuel pump would be good for light tune or would i need a bigger one.

[Johnnynz]

I have personally seen a factory pump support 200 KWatw (No guarantees on how legit the tune was however). But at a price tag of $160 and piss easy to self install its something I would do for piece of mind and the pure fact there a pain in the arse when they fail.

That is of course if your pump has done 100,000+. Mine shat out at approx 120.

[Joker]

is a 500hp walbro good for 500 BHP or is it a litres measure etc?

[whatchain]

hey funky, what about the fuel pressure regulator? would i need to uprate that as i will be running a high volume fuel pump? or would it be able to recycle the fuel back alright?

[Guest]

First thing I was told to upgrade on my car when I was modding was the factory fuel pump.

[funkytown]

fuel pressure regs if you are using factory ones are fine.

You can either use one factory one in the normal rail set up, or you can use two factory ones in a split rail (like i do) or use an aftermarket reg set to factory base pressure in a split rail ocnfiguration and they will all work just fine up to a lot of hp .. more than what a walbro can flow anyways

In short a factory reg will be fine

you should just upgrade the pump to a walbro for the $$ concerned.... if it dies.. 2 seconds of WOT and no fuel and you\'re up for a new motor.. bank $8k for a good rebuild easy...

 ballsrburning said:

First thing I was told to upgrade on my car when I was modding was the factory fuel pump.

very good advice imo.

[whatchain]

thanks, i have just brought the fuel pump. hopefully once i get everything installed. i will get good results after tune.

[funkytown]

remember to reuse the factory sock, you will see when you hook the pump out. throw the walbro one in the bin and DONT USE IT.~!!!!!

[whatchain]

oh ok. just curious, but why?

[funkytown]

the walbro one doesn\'t sit right in the tank, and seems in every case they are used to induce fuel surge at levels as high as 1/2 full. this is totally unacceptable.

The factory sock seems to work perfectly and doesn\'t need replacing.

[Joker]

Think i used the new one

[Guest]

 funkytown said:

the walbro one doesn\'t sit right in the tank, and seems in every case they are used to induce fuel surge at levels as high as 1/2 full. this is totally unacceptable.

The factory sock seems to work perfectly and doesn\'t need replacing.

+1 on this I have seen that, all be it in a race car, so have installed a surge tank plus another external fuel pump.

[Koom]

 JoKer said:

is a 500hp walbro good for 500 BHP or is it a litres measure etc?

Its more a correlation from the 255LPH they put out at a given pressure. The flowrate drops as the output pressure increases i.e. it flows less (power).

[Stoffa]

 JoKer said:

Think i used the new one

so did I and when im less than 1/4 tank and do a hard pull in a straight line it hits my fuel pressure GP cut set up on my link.

not ideal but I have that safety cut there so im not too worried about it, just keep the tank full

[Timmah]

Is it as easy as buying the subaru specific one, rewire, use stock sock, fit. Drive away happy?

[Johnnynz]

 Timmah said:

Is it as easy as buying the subaru specific one, rewire, use stock sock, fit. Drive away happy?

Yes it is. Took me about an hour and I am a Mechanical retard who got the wrong rubber mount lol.

P.S. If the Subaru sock is in poor condition it might be worth sourcing another. But I wouldn\'t use the Walbro one either.

[Timmah]

 Johnnynz']

[quote name='Timmah said:

Is it as easy as buying the subaru specific one, rewire, use stock sock, fit. Drive away happy?

/quote]

Yes it is. Took me about an hour and I am a Mechanical retard who got the wrong rubber mount lol.

P.S. If the Subaru sock is in poor condition it might be worth sourcing another. But I wouldn\'t use the Walbro one either.

Rubber mount? I think I\'ll add this to the to-do list.

[Johnnynz]

They come with a rubber mount to make them sit right, mine was wrong and I had to hack at it a little to make it sit right.

Was still about an hour job.

If your in anyway intimidated by the job do a quick Google, theres a heap of how to photo guides for various years.

[whatchain]

i have finally got the fuel pump out of my car. im a lil surprised to see that the pump in my car is actually bigger then the walbo one on going to be replaceing with?? almost twice the size. the thing is, my pump doesn\'t even look like the one on sparks link. http://www.clubsub.org.nz/forum/index.php/topic,292.0.html . can someone tell me if that is the factory pump or is that a AF already fitted?

[Joker]

heres my "diary" of installing my walbro (with pics)

http://www.clubsub.org.nz/forum/index.php/topic,27739.0.html

3rd pic looks exactly the same/OEM to me

[whatchain]

so im guessing in this case. size doesn\'t matter? just want to make sure before replacing.

[funkytown]

i remember when i did mine (a few years ago) i noted the factory one was noticably larger than walbro.

[Guest]

Size doesnt matter there are two common sizes of fuel pumps 38 and 51/2mm. They fit most jap vehicles depending on pickup locatioon. I had the large 52mm pump in my V5 and small 38mm in the same era p2 foz.