I own an Evo 9 and right now it has basic bolt on's, but Iam looking to modify it further with cams and a bigger turbo. I am shooting for the 460 whp mark. What size fuel pump would you suggest I go with to reach these numbers. Right now it's got a Walbro 255lph. Also what size injectors would be needed for this amount of hp? I live in Colorado so it will be tuned on 91 octane.

 

Having a number goal makes things kinda tricky. There are alot of factors such as fuel, what kind of dyno, air density (such as living in colorado) and what not. If you were shooting for 460whp on a dynojet with 91 octane I would probably go with a double pumper setup. A single 400 would probably do the trick but by spending the time and money on a double pumper, you are now set for the rest of the time that you own the car when it comes to fuel stuff. As far as injectors go, you can maybe run a set of 1200's or so. Since you're using 91 and gonna be at high altitude, you might want to think of throwing in a meth/alcohol setup or finding E85 to help you with the amount of boost you'll be running to hit those numbers. Maybe hit up the local guys that are making that kind of power?

 

So I was researching the deatschwerks 340lph fuel pump. From what I have read it's a drop in that requires no modification to the pump housing and claims to be E85 compatible. Can someone please chime in if you have any kind of experience with this pump. How much hp could I extract from this setup? I went ahead and bought a set of 1200cc deatschwerks injectors. I hope I am happy with them.

 

Heres a thread that discusses that pump

https://www.evolutionm.net/forums/ev...uel-pumps.html

 

Modify the housing for a walbro 450, do a proper dual voltage rewire and never worry about the fuel pump again.

 

Thats good advice for e85 for sure. The aeromotive 340 would be a better choice compared to the dw300.

 

Your 255 will do you just fine. If you are worried, rewire it and punch in the relief a bit. The 255 is known to do close to 500 on e85.

As injectors are concerned, Id look into something equal to or above 1200cc if you stay low impedance.

This is my current setup on my gtx3076. (Close to an fp red, just a touch larger)

Once I tune it I should be around 450-475hp.

 

Yea, no. Its either a walbro 255, which won't flow enough. Or just put a 450 in it. I think you've been told multiple times that your pump of choice is not as good as you think it is..

 

The 255 is a old design their are better options. 255's are loud I can hear mine in my 2g outside the car with it idling if its under half a tank. ( I have tried multiple pumps) The 450 is the best option for e85 hands down Ive said this multiple times as you have also. I like my aeromotive stealth though and I know for a fact its good for 660whp on pump gas.

 

Maybe not as good as I think still better than a 255 :P

 

How many Hp is a Walbro 255 good for ? and what are the differences between lph and non lph?

 

255 is good for about 500 maxed out. lph is liters per hour there is a high pressure version I think thats what you mean.


255 liters is the volume of fuel that the pump will flow at 40 psi. While this is a more accurate rating than a free flow rating, the 255 lph rating is only accurate if you are running your engine at 40 psi and your pump is being supplied with 13 volts.

Sometimes pumps are rated based on pressure. For example the Walbro 255 lph pump is capable of producing a pressure in excess of 100 psi. While this information may be relevant, it only provides one detail about a fuel pumps capability.

The better way to select a fuel pump to use in your fuel system is to consider three factors:

How much horsepower your engine will produce.
What fuel pressure is required for your engine.
How much voltage is supplied to your fuel pump when the engine is running.

 

Which not even a stock Evo runs at WOT. In fact it runs more fuel pressure at idle than 40psi.

People need to look at 60psi+ fuel pressure and voltage when looking at fuel pump output, which I believe is your point...

 

So back on topic I'm trying to get to the same power as the OP I have the 450lph was planning on using stock harness for power. but in the case I do need more fuel how do I rewire the pump to see higher voltage

 

You need a dual voltage rewire. The easiest way is to use a hobb's switch to activate a 10g supply from the battery and splice into the pump power wire right at the sending unit. mrfred has a thread on it in the how to section.