This is from Forged Internals website......

The Walbro 255 in tank pump is a drop in replacement for the stock 350Z/G35 fuel pump. It flows more than 3 times the volume as the stock pump, and is a necessary upgrade for any time of forced induction. Good for 650-700whp on the 350Z/G35 FREE GROUND SHIPPING 48states

What does the stock pump flow ? (140lph) ? 255/3=85? Hu ?

What does the Vortech inline pump flow ? (155lph) ?

Can I say that the stock vortech system (fuel Pumps) will flow 295lph with correct line size, rails, injector size, ect. ?

Fuel System Experts Please............
Please talk about LPH for X amout of HP, Ect.

 

Bump

 

The vortech FMU/Aux fuel pump is not in parallel with the stock pump...see fig 7-c of the install manual.. Believe it raises the fuel press to the injectors...

 

You are Correct........ That is not one of my questions, but thanks.
The Vortech is In-Line. SO...........
What is the Total flow in LPH of the Vortech System (given the Specs from the start of this Thread) ?

 

What you basicly are trying to find out is....Can you run the Vortech aux pump instead of the intank walbro pump ? Correct ?

I think you could do it that way . But you would have to change the washer in the FMU , so it doesnt increases fuel preasure as much . Be it 1 to 1 or higher , I wouldnt know . Or get a FPR to increase fuel preasure .
Gman might know...he was running bigger injectors with the walbro and the stock fuel rails when he had the Vortech SC on his car

 

Thanks for bringing this my attention, I just updated the website to reflect that a single Walbro 255 is good for roughly 550whp, rather than 650whp.

The stock Nissan pump, I have been told, flows about 90lph. If someone has any additional info or confirmation, please let me know. THANKS!

 

my fuel economy is really bad right now. COuld it be coz of the walbro 255? if so, would making it a return system fix that?

 

Yes, without a return fuel system, and FPR, you will experience excessive fuel pressure at idle and cruise, which will result in decreased fuel economy. A return fuel system, with the FPR properly dialed in will return your fuel economy back to normal.

 

couldnt adding a universal FPR be able to return the pressure back to 52 at idle and save the gas? Also, is all fpr 1:1?

 

Ha-I average 10-12mpg with my set-up

 

Could this be because you really like the skinny pedal??

 

This will depend on the setup though. If you run a Walbro 255 lph pump but modify your FPR you should be running the same base fuel pressure 53-55 PSI as stock.

 

That might have something to do with it...

 

that is a difficult question to answer. Most EFI pumps are rated at around 43 psi (3 bar). In your vortech application, the pump is going to flow much lower than its rating due to the significantly higher fuel pressures under boost (could be in the 100 psi neighborhood.)

kinda funny. Your injectors can squirt more fuel for a given pulsewidth at higher fuel pressures, but the pump will flow less.

anyway, I think this is the pump that comes with the vortech kit. It is their inline 155lph unit. they don't mention at what pressure this rating comes from.

 

Sharif what if i wa aiming for 600 or 625 something like that whats the solution ( get a biger pump)??

 

this is an old thread but an interesting conversation.

did we ever find out what it flowed together (the aux and the stock)?

 

I am also trying to figure this out. I have an inline 255lph pump, and I am wondering if I need to do a fuel return and a FPR. I am only looking for
400whp though. Hopefully I can just put the inline pump with the 550cc injectors, and tuen it out with UTEC.

 

I think this would increase the pressure of the system unless you run with something to limit the pressure since the inline will be running all the time.

glad you received the pump! I'll stop bothering UPS now

 

To find out how much more fuel is availablewith the same size injectors afte a pressure increase, use this formula.

Divide new pressure by old pressure. Find the square root of this number and mutliply this number with the old flow rate.


You can get alot of info from RC engineering's website

http://www.rceng.com/technical.aspx?...GUEjAWDlVTb6CW

 

^ thanks! now to just find out what the fuel pressure increase really is with this combined aux fuel pump + stock in tank.