was wondering power ranges for them and which is better for buck

 

STM put down 550+ on a walbro 400 with fp red. I'm going to prob max it out with a fp black and see what I can make before a BR double pumper is installed.

 

what are your power goals? the 400 isnt a drop in, requires modding of the housing & should be ran with an adjustable FPR. the 255 modified flows enough fuel to support 500whp on e85 and 600whp on 93oct and will work fine with stock housing and stock FPR.

 

http://www.maperformance.com/blog/20...maperformance/

comparison via map. i had a 255 with no problems at 350whp for 20,000 miles. going to the 400 cost me the pump, mod to pump housing, and a fuel pressure regulator kit.

 

400 is the best bang for buck. I've heard of a couple guys taking out their dual 255's and installing a single 400.

Ray Pampena has done 650awhp (E85) with a single Walbro 400.

 

You don't need a fpr with a single Walbro 400 as long as it is not hotwired and you are using the stock low/high voltage circuit. I would look to mod the low/high voltage switchpoint as the fuel pressure will bounce around at part throttle acceleration.

https://www.evolutionm.net/forums/ec...ion-table.html

 

How much will the 400 support without being rewired though?

 

Fwiw, since no one EVER mentions them... I'm running a DW301 because I've had Walbros in other cars, and I loved everything about the Walbros but the intermittent LOUD whining.

My DW is super quiet, and I have no problems with fuel delivery. But I'm not shooting for high HP. I just wanted something that wasn't the first thing people notice.

 

Safely 500hp@wheels on stock fuel system, but likely more.

 

Depends on your hp goals. But out of the two I would go with walbro 250.
On my gsx I use aeromotive stealth 340lph. Its a stock fit. Check it out.

 

i think it will depend a lot on the condition of the factory relays, connections, and alternator. i'm working on a solution with spoolinup that will retain factory low/full voltage but allow maximum possible voltage that the alternator can supply.

 

I forgot about being able to use that table. Maybe drilling the hole larger in the T siphon helps some also, not sure.

a modded walbro woops the DW's *** at high psi. Also if your walbro is whining then you either have a clogged fuel sock or its about to die. walbros do not whine when they are running properly. I've experienced the whine stuff first hand on them myself.

Ya id say more. Not sure how bad the 416 drops pressure at around 100psi though. but based on walbros flow testing, the 416 is a badass little intank pump, and whoops on the modded single walbro 255. However i have no first hand experience with that pump, and i know you do. MrFred / Mychailo did a lot of testing with it also and approves it.

that sounds awesome! a rewired fuel pump direct to the battery (not physically (big bonus)), where you can get the max performance out of it, and still have the luxury to keep the stock FPR. that is something id buy! a stock ecu boost a pump that sounds like.

 

Based on my testing, I'd say that at 13.0 V, its good for 550 whp and maybe as high as 600 whp.

Yep. Matt's getting the parts together...

 

I don't want to start a fuel pump debate here because I liked the Walbro. I also won't argue about what the high Psi numbers are, because I don't know, and I don't actually care for my HP levels.

But the whining point you made just isn't accurate. The pump I had whined all the time, and it was just louder under certain conditions. Fuel pumps make noise. That's what they do. The Walbro is just louder... that shouldn't necessarily be a hit against them... sometimes mine was stock pump quiet, and sometimes it would be crazy loud.

 

I will agree about Walbro's being noisy. I've had 255s in a couple cars and they were all loud. I don't personally care about that, but I had the same 255 in my Evo for 2+ years with 10k miles of track driving and no issues, but it was loud as hell.