Larger Fuel Pump Recommendations & Hardwiring

My walbro 255 has served me well, but I will likely be upgrading to 1000cc injectors and E85 and I believe I will need a larger fuel pump.

 

I am looking at the DW300c and Walbro 400 as replacement options, but I am concerned with the reliability of the DW based on some of the posts on the forum. Any feedback on which will be best?

 

That leads me to my next question regarding upgrading the fuel pump wiring. I have read through Turkeylord's guide, but I am confused whether this just lowers the cable resistance to the fuel pump or if it also wires the fuel pump directly to the battery? If I purchase the DW fuel pump cable kit am I good or do I need to purchase separate relays?

 

Thanks

I ran a 300c in my car and it worked great. I would certainly put another one in. They are designed to run on E85.

That said, I think your 255 would be large enough to feed the 1000cc injectors. The 255 is rated for roughly 257 liters per hour at 40PSI. That would equate to 4.28 liters per minute. With 1000cc injectors, (assuming an average of 1000cc per minute times 4 injectors) you are only requiring 4 liters per minute. Should be fine if you want to keep it.

 

With regards to the wiring, you are correct that it runs a cable from the battery to a relay, then through the fuel pump module, then to the pump. You upgrade the wire size to allow less voltage drop. The DW fuel pump kit is a nice unit and has most everything you need. You may need some extra wire depending on how you route. I assume you are talking about this:

 

https://www.amazon.com/DeatschWerks-FPHWK-Fuel-Hardwire-Installation/dp/B009PJQFQA

 

In addition, make sure you read the updates on the wiring in the Turkeylord thread. The original method allowed a small battery drain and would run the battery dead after a couple of weeks. The fix is in the thread and solve the battery drain issue.

Thanks for the insight. I am not 100% sure about the math, but I thought if I run 24psi and add this to the base fuel pressure, then the pump would only be flowing 225lph.

Do you have top feeds or are you staying with side feeds. The side feeds flow a little less. (~900cc) You could be getting close if you start to run IDCs above 90%. It would also depend on your boost taper towards redline. If you start to run out of injector up top, you can still have your low end punch and taper boost at the top end. What kind of engine mods do you have to run 24psi? If you don't already, you'd want to look at different head studs as the factory studs will stretch allowing the heads to lift around 21-22psi increasing your risk of blowing a head gasket or eating coolant.

I have an opportunity to pick up some DW sidefeeds for cheap which flow around 970cc. The top feed conversions kits are going to cost almost $1K all in which is more than I want to spend on the car.

 

I have a built block with ARP2000 headstuds, and running a TD05-20G. I think with the 1000cc injectors my IDC would be 90-95%.

Nice! Sounds like a nice build!

Don't use big sidefeed injectors. They're a pain in the ass to tune and very unreliable. Pony up for the topfeed conversion.

Totally understand, but really don't really want to spend $1K on the topspeed conversion.

 

It sounds like I am going to have to upgrade since the Walbro 255 can only really support around 220LPH when running 20+ psi of boost which would be less than the 1000cc injectors could support.

 

My fuel pump assembly is already trimmed for the Walbro. Does the DW300c need trimming to fit?

Dw300c, AEM 50-1215, Areomotive 325, and the eBay specials (with painted bodies and colored caps) are all no trimming plug and play. It's strongly suspected that all of the above are actually made in the same factory in China. They all perform the same down to power draw, just have minor differences in in seals/materials and QC.

 

That said, if the filter was already hacked up they probably won't mate correctly. Get a new filter, they are about $40. It's 12 years old now and probably needs to be replaced any way.

The Aeromotive 340 looks nice and isn't that expensive. Since my fuel assembly was modded to fit the walbro 255 would this cause issues since the Aeromotive 340 is slightly smaller?

Edit: the following is WRONG on the Areomotive 340, got it confused with the 325 drop in

 

Yes, the Walbro 255 install involves hacking up the mounting ears for the pump inside the fuel filter. It's not so much a factor of size as it's a factor of the top of the Walbro had a different shape that nessetated removing those ears.

 

You'll need a new fuel filter so the Areomotive pump can mount properly.

USA made: 42072AG16A

Japan made: 42072AG140

 

You'll want to put in new o-rings with that.

USA made:

3x 42025AG09A

1x 42025AG10A

Japan Made:

3x 42025AG070

1x 42025AG080

 

And your pick up strainer probably has seen better days. The Areomotive may come with one (designed for a Honda) but can get a new OEM with the proper shape for ~$5

USA made: Denso 952-0090

Japan made: Denso 952-0086

 

Edit: the Areomotive 340 is the same size as the Walbro, so requires the same mounting. Disregard the above unless going to a "drop in" style pump.

I had initially installed an Aeromotive 340 on my E85 LGT and as I recall, it was not a drop in pump. I had to modify the housing similar to the Walbro 255. I also had to modify the top of the pump. Below are the notes I followed when I did it. After about 6 months on E85, I started having fueling problems and pulled the pump. The outside of the pump had pockets of rust formed on it. I ultimately pulled it an went with a DW300C and never looked back. It was a true drop in pump and worked well.

 

http://legacygt.com/forums/showthread.php/which-aeromotive-340i-171322.html?t=171322&highlight=aeromotive+340

 

http://www.iwsti.com/forums/2-5-liter-litre-factory-motor/223636-aeromotive-stealth-340-lph-direct-drop.html

 

http://legacygt.com/forums/showthread.php/installed-aeromotive-340-fuel-pump-today-177995.html?t=177995&highlight=aeromotive+340

The aem320 is my go to pump for anything in that power level.

 

I would stay far away from high volume sidefeeds...i realize its expensive but there is a reason why people go that route for top feed conversion. I will NOT even calibrate anything larger than 850 side feeds due to inconsistencys in fueling/latencys and failure rate.

 

Just my .02 as i know we have worked together in the past.

 

Oherwise it sounds like you should have a fun build with the new block

 

Dave

Nice! I didn't know AEM made that pump. Are they new to the market. (by new I mean within the last two years?)

FWIW, I've been running a Walbro 255 on 1000cc injectors (top feed, 3 years of DW and 2 of ID) with e85 and a BNR68 at 24 psi peak boost for 5 years now.

They (aem) supply a drop in fitment now for the lgt/08 wrx and i have had great luck with it. Got tired of seeing high rpm pressure drops of the 65c.....the walbro should support it as well, 255lph is a good amount of fuel.

 

Dave