At a base fuel pressure of 43psi 30psi of boost your at 73psi and your 400lph pump now flows 235lph..... That Aeromotive 340 flows 390lph at 70 psi. Hard to argue with numbers.

 

Why do you keep quoting the 255 numbers and saying it's a 400 or even a 450 (which this thread is about)?

Here is one test with an actual Walbro 400 and 450 E85:

https://www.radiumauto.com/Blog/Post...-Pump-Test-100

They beat the 340 in every single test.

The 400 flows approx 320lph @ 5bar and the 340R flows less than 250lph @ 5bar.

The 450 E85 flows 350lph @ 5bar and the 340R flows less than 250lph @ 5bar.

"Hard to argue with numbers." You keep stretching the facts to support your claim, showing 255 data as 400 and taking the 12v low amp flow numbers of one pump and comparing them to 13.5v high amp flow numbers of another pump.

Come on now.

Here is a Evo centric test that mrfred did with the 400 pump that might be helpful to people: https://www.evolutionm.net/forums/ev...testing-2.html

And another he did with the 400 vs 450: https://www.evolutionm.net/forums/ev...6-testing.html

 

Good info. I'll be running a 450 soon

 

I went 9's in a full weight Evo on a single pump. You do the math. Enough said.

Go ahead and punch the pressure relief valve down on the walbro 255 and re-test it against the A340. Stop digging on the net for 3rd party data, I have real world results.



Here is a secret. If you want a legit 700hp+++ out of a walbro 450 (E85) you must re-wire the pump with a dedicated ~10awg power AND ground. Would you put a 6766 on a stock exhaust? I think not. Same reasoning. Also, you MUST bypass the internal fuel filter and run a dedicated ~-6an feed line to an aftermarket fuel rail with some 2000cc++ injectors.

This is not new data, the walbro E85 pump is actually OEM equipment on many high horsepower OEM vehicles, and when the voltage is increased the flow does as well. (think 15-17vdc)

 

According to my PM's, MrFred stated that a -6AN feed line to a high flow rail with a hardwire kit, drilled siphon on the OEM return and 1650's should be good to ~570whp or so.

I didn't ask him about bypassing the internal fuel filter on the 450, but it's a good question.

 

Beyond these tests; take it from me. That wally 450 will do some work if setup properly.

 

Bumping this thread for some help I'm getting frustrated, I have a 2.4, curt Brown head, intake manifold and tb , gsc r2's, fic 2150's, ets 4' intercooler tubular manifold, and apexis version of a 35r. Looking to make 600whp anything over is a plus. Here's my dilemma I have a walbro 450, return siphon is drilled and I'm going to run ethanol. I'm tried of guys trying to sell me a double pumper when I call and ask when I think this can hit my goals
With this pump they don't say wether it Will or won't they just say the recommend a double pumper. I appreciate the help as always guys

 

Run a 6an feed line and it should do it.

 

Thats impressive

 

I'm not looking to do that yet, what's funny is the same place I bought the pump and not from has on their website that it will make over 600wheel. But I called to talk about a rewire I get told to run a double pumper lol

 

Why no? It's really simple. Just an adapter fitting for the fuel rail inlet, and 6an quick release fitting for the fuel sender. My car made 565whp VD at 80-85% duty cycle with 1650's and the walbro 450. The 2150's will help, but idk when the pump is going to run out of fuel.


It also depends on how much boost you have to run. More boost equals higher fuel pressure, which means the pump flows less.

 

Probably going to be around 35psi

 

If it takes that much boost, you may run out of pump due to the increased fuel pressure reducing pump flow.

 

That's just what I'm guessing, I'll give more info so it can help on this previous set up it made 465/439

2.4 stroker
Stock port head with bc 272
Stock intake manifold and tb
Pre 880 injectors on 93
Walbro 255
Buschur cop kit
3' ets intercooler

New set up
2.4 stroker
Curt Brown head with gsc billet r2's
Curt Brown intake and tb
Fic 2150
Walbro 450 with stm braided line from the firewall
Buschur cop kit
4' ets intercooler

So I made some substantial improvements in the air flow of the setup, so it might not take 35psi from the 35r. I know curt made 655 iirc on a 35r

 

If your riding on the edge, there are companies that sell voltage boosters for the fuel pump. From what I have heard most fuel pumps really improve from increased voltage. I would think increased voltage would especially help at higher line pressure too. I believe some mfg's publish their flow numbers at higher voltages as well.