1FastT2

iTrader: (1)

Currently I have a Walbro hp 255lph fuel pump. Will this flow enough fuel to support approx. 400 to 450 rwhp? If not what is suggested?

rx7_turbo2

I know of a bunch of people who will be running that type of power and they all have a Walbro. A rising rate fuel pressure regulator might also be a good idea, and how big are the injectors your going with?

1FastT2

iTrader: (1)

I have (2) 550cc & (2) 1600cc injectors.

RETed

400 to the wheels is about as far as I would push a Walbro 255lph.
Anything more, I would recommend a Aeromotive single or dual Bosch fuel pumps.&nbsp Hell, you can go twin Walbros if you want - this seems to be popular with the Supra crowd...


-Ted

E6KT2

Ted, can you post some more info on the Aeromotive Fuel Pump? I thought the Walbro would have been more than enough for my application, but now I'm not so sure. Thanks a lot.

RETed

http://www.summitracing.com/
Part number: AEI-11101
500lbs/hour @ 12VDC @ 45psi
http://www.aeromotiveinc.com/products/1000hp_pump.shtml
This is ~80gph (6lbs/gallon).
Walbro 255lph = ~66gph - hmmm, not that much gains.

Bosch makes a 300lph fuel pump - available from Kinsler Injection.
300lph = ~79gph, just about the same as the Aeromotive pump.



-Ted

maxcooper

Pump performance can't be accurately described with a HP rating. Figure out the maximum fuel pressure you will be running, and see what the pump can flow at that pressure.

But, if you want to make 400-450 HP with a Walbro, it would be wise to keep the fuel pressure down so that the pump can flow enough fuel. You could run into trouble quickly with an adjustable RRFPR. It would be bad if your fuel pressure goes up to 80 psi or something under boost. The pump won't flow much at 80 psi.

Here's a web form that can help you determine your fuel pump requirements:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

-Max

Morbius

Seems to me that that fuel calculator that Max posted says the Walbro would be a few gallons over need for my setup which will be similar to 1FastT2.....But I am not sure on the accuracy of the calculator either

-Morbius

maxcooper

I tried to be pretty conservative, with a large pressure drop as the default, on the fuel pump requirements calculation.

Be sure that you are using measured pump flow data to check its suitability, as it will not flow 255LPH at any pressure. Rather that is the flow just at one pressure (probably near 43.5 psi). For instance, it will probably not flow anywhere near 255 LPH at 70 psi. To judge a pump, you need pressure and flow numbers to compare to the pressure and flow graph of the pump. That said, I wouldn't be surprised if the Walbro pump was adequate for 400-450 HP as long as the pressure is not too high.

-Max

vmb

where should i buy a walbro fuel pump?

E6KT2

Is that Aeromotive pump external? How hard is it to hook up an external pump? Thanks.

qwck10th

Based on my (often suspicious) math, the answer is no, the Walbro won't support your goals. Here's my work http://www.se-rx7.com/images/fuelpumpgraph.jpg This graph assumes base pressure of 40psi and a 1:1 rise in fuel pressure : manifold pressure (up to 20psi). My goal is to make 450bhp at 15psi. Based on several available fuel calculators, I'd need 64gph at 55 psi. This is well beyond the Walbro's capabilities (assuming the graph is correct). Once again, Ted is right. I think the big ND pump (for $250) will get the job done, affordably - w/o replumbing.
All best,
Steve C.

Jedon

Can the stock pump be used in conjunction with a walbro to make up for the lack of fuel or does the mighter pump win?
-Jedon

93blackr1

Just use the following and be done with it:
Aeromotive EFI Filter # 12302
Aeromotive Pro-Series Fuel Pump # 11102
Aeromotive EFI Filter # 12301
Aeromotive Y Block
Aeromotive A1000 Fuel Regulator # 13101
-10 Teflon braided feed line (Aeroquipe)
-8 Teflon braided return line (Aeroquipe)
Custom fuel rail (RC eng.)
More than enough for 600++rwhp.
Just my .02 cents

jspecracer7

Twin Walhboro's would be suffecient...just ask Igy.

Twin FD fuel pump's should be enough as well. From what little knowledge I have, FD pump's are 170 lph, so two of them should be suffecient. Doesn't soulassassin run twin FD pumps?

Either way, I think that I'm going to go with the twin walhboro pumps. Fairly easy to install, and should be suffecient to produce the fuel for the horsepower that I want.