R33 Stock Fuel Pump Compared To Walbro Gss-342

[RBwhatever]

I just checked mine now. Its sit on 9.5v at idle. We held the revs at 3000rpm when stationary and it sat on 13.5v. So it seems as though if it was under full load it would hit 14v.

The wires I have aren't all that big. Maybe its got more to do with amps more than volts.

[RBwhatever]

Just read the thread on here about doing the direct feed mod. http://www.skylinesaustralia.com/forums/in...showtopic=91993

It seems it's not really needed for R33's.

So if in fact it does start to run lean at high power outputs it's just running out of puff.

Such was the case with you Jono. It started to run out of puff around 300rwkw yes?

[The Mafia]

The pump shouldn't really be rated on power, but pressure.

As you can see in the flow chart, the more boost, the less flow it will be able to push against it.

Remember, the skyline rail is 42psi, and if you are running 18psi, then thats 60psi the pump has to push. As you can see, it runs out of flow beyond 60psi.

But power wise, I wouldn't go anything over 270rwkw, and 15psi, as anymore will stress the pump causing it to fail early.

Edited September 12, 2007 by The Mafia

[RBwhatever]

But if in fact the GSS-342 is a high pressure pump as everyone seems to state, it should be capable of pushing 80psi of fuel with decent flow with ease.

I don't quite understand the relation of boost pressure to fuel pressure though. I can understand more fuel pressure results in less flow. Is it for example, 18psi on any turbo will result in 60psi of fuel pressure?

[The Mafia]

well, think about it.. there is 42psi in the fuel rail to maintian the normal pressure behind the injectors. What about boost pushing back up the injectors?

The fuel pump needs to supply 42psi to the fuel rail, and then another 18psi to "counter act" the boost.

That means a total of 60psi, to maintain 42psi in the fuel rail.

NOw have a look at the 255lph walbro in the chart I have supplied - as soon as the fuell pressure goes above 60psi, the fuel flow drops dramaticly.

And yes, any turbo running 18psi, a T88 or a GT2530. Obviously these turbos would need different flow requirments as the engine with the T88 is flowing more air and require more fuel injector duty cycle (injectors are open for long periods) and needs more fuel flow.

The Lower Specced walbro runs 255lph at 42psi.

I got a Nismo 275lph at 70~psi. BIG difference.

Higher flow at Higher pressure means the pump has more "torque" and can handle larger fuel loads.

Edited September 12, 2007 by The Mafia

[RBwhatever]

Hmmm yes, it all makes sense now. Its as you said, they shouldn't be rated by power, but rather flow at XXpsi.

Thanks for the insight Jono

Edited September 12, 2007 by KeyMaker

[seriesII]

Bringing this from the dead.. thought i'd save a new thread..

Can some one help me out abit.. just put in a walbro 341 in a r33 s2 gtst.. runs great.. feels much beta to me.. but maby thats the idea in my head i put one in?..

any ways.. it fixed abit of the issue with 10psi boost in lower revs.. i would normaly feel like im cuting in and out.. Will the stock fuel regulator be ok for 200rwkw?.. with stock injectors?.. or do i need to change the regulator or injectors if i have extra cash.. thanx

oh and.. can i buy a new fuel pump filter sock, the standard nissan one anywere?.. or do i need to order from nissan?.. thanx

Edited June 29, 2010 by seriesII

[KiwiRS4T]

Walbro do a Nissan kit which presumably comes with a new sock so maybe try your Walbro supplier for the sock. Stock fpr and injectors should be fine for 200kw. Rewire your Walbro as per the DIY threads - not just for more flow up top but for longer pump life.

[SimonR32]

Don't worry... Mafia has not a clue in regards to the pumps! 340, 341 and 342 are all the same 255l per hour pump that can easily handle decent power and boost

[seriesII]

Walbro do a Nissan kit which presumably comes with a new sock so maybe try your Walbro supplier for the sock. Stock fpr and injectors should be fine for 200kw. Rewire your Walbro as per the DIY threads - not just for more flow up top but for longer pump life.

hi ,thanx for the help.. i got a nissan walbro kit.. but the sock is sooo short it makes the nissan one look like god.. when your saying rewire, you mean to increase the voltae right?.. working on that next.. might be a silly question, but what open wire do i touch with the multi to see whats volts my pump is running at?.. thanx

[rondofj]

putting in my GSS342 tomorrow - got some metal crimps to connect the pump wires to existing - as I dont have any solder devices.. Is this safe???

[rondofj]

actually its 2 metal crimp type connectors with a blue insualtion cover around it - u crimp both pieces to the ends of the 2 wires and then those connectors - male and female, click in together.. Cant find pics of this on the net - wonder if its safe?? like fire safe as it will be in-tank??

[scotty nm35]

Of course, the pump is designed to go intank. Just make sure they are crimped properly. The best would be to solder and heat-shrink the connections.

[rondofj]

ok, I just thought that those exposed crimp connectors will have current flowing through it - current = spark = fire in a tank of fuel! I know I'm missing something here tho..

[The Mafia]

can't spark when it is under the fuel - There is no air for spark

[rondofj]

I knew I was missing something - no air! Becoming a bit of a bonehead now I guess - actually I think there r pockets of air in fuel, water etc, how do fish take in air through their gills? .. Who cares as long as my fuel tank doesnt catch fire lol..

[rondofj]

Can the pump run without the sock - I'm just worried about my sock falling off, I used the stock sock with the stock pump isolator cap as I didnt get a sock with my walbro (lost the retaining pin) - it is tight now but has a bit of play and I'm worried bout that.. The bosh 040 install in the DIY didnt go about installing the sock..

[scotty nm35]

Can the pump run without the sock - I'm just worried about my sock falling off, I used the stock sock with the stock pump isolator cap as I didnt get a sock with my walbro (lost the retaining pin) - it is tight now but has a bit of play and I'm worried bout that.. The bosh 040 install in the DIY didnt go about installing the sock..

The sock stops particles getting into the pump and causing damage. I have about 10 of them here, pity you're not local. Just fit it like it is for now and pick another one up later.

[Julzillionaire]

Can the pump run without the sock - I'm just worried about my sock falling off, I used the stock sock with the stock pump isolator cap as I didnt get a sock with my walbro (lost the retaining pin) - it is tight now but has a bit of play and I'm worried bout that.. The bosh 040 install in the DIY didnt go about installing the sock..

How did you go fitting it? I read somewhere on this forum a guy buying a standard Falcon V8 sock from autobarn.

[R6n350GT]

i have upgraded my 350z fuel pump to DW 300ltr one so have a newish pump, is it better than my 33 one or leave 33 as is? sorry to bring up old thread