Anyone here running their fuel system like this?

[Shocker]

Well I'm going to be need more fuel for my new setup this year. However I really don't want to run a surge tank it seems like a hassle and not entirely needed at least from what I think.... could be wrong. I've been searching for a few hours now and am having trouble finding someone whose running their fuel pump(s) like this.

Using my currently intank walbro 255 as the lift pump, but not using a surge, and off that same feed line, running the 044 bosch then to the fuel filter, the fuel rail, into the FPR and back into the tank for return.

Anyone else running a fuel setup like this? I don't see why it would be a problem... I just like getting confirmation.

hers my **** drawing.

[Carl H]

the 044 on its own is plenty...i figured it out and you can make ~600hp before you need to upgrade...with a little bit of finesse you can get the o44 to fit in tank too, course on a s13 its cake on my s14 it took the better part of 3hrs to manhandle in.

[Shocker]

yeah I really don't even feel like opening the damn thing so I'm just going to run it like I drew.

I'm just gonna be on pump gas for now... but if I get greedy this summer I will max just the single 044.... granted of course I have no more gay issues, in a few weeks I shall know for sure.

[krayton]

isnt that only gonna run what the 255 can push?

cant you just run a sump like all the aussies do?

255 fills the sump up and your aftermarket inline fuel gets it from there

[Shocker]

isnt that only gonna run what the 255 can push?

cant you just run a sump like all the aussies do?

255 fills the sump up and your aftermarket inline fuel gets it from there

um no, either way it ends up just being the bosch pump actually doing the work for both setups, the bosch will just over power the walbro in this case..

I guess I'll know more for sure when shes on the dyno, I'll be monitoring the FP closely. I'll see how much the walbro actually helps....

I posted this on SAU, one thinks it will add to help the bosch the other feels it will just be the bosch doing the work.

[Darius]

Just to add some insight as to how pumps in series operate:

Both pumps will flow the same rate of fuel but at different pressures. If both are operating simultaneously, the walbro will be pumping from atmosphere up to a pressure along its curve based on the flow the 044 is drawing. Let's assume 25 psi. The 044 will see the 25 psi provided by the walbro and create enough pressure to push against the fuel pressure regulator plus the frictional losses of getting the fuel to the engine. Assume 43+25 lbs of boost=68 psi. The 044 will flow the rate where its curve crosses the 68 psi axis. Whatever is not used by the engine, returns to the fuel tank.

The flow and pressure are inversely proportional (for practical purposes) meaning that if a pump is required to flow more, it will provide it at a lower pressure. The difference depends on the pump curve of flow (x) vs. pressure (y).

To truly know what is going to happen, one needs the pump curves for both pumps and the voltage that will be supplied to each/both. From there, it can be determined how much head each will provide and if that will be adequate for the boost and power levels that you are aiming for.

[Shocker]

good info Darius, you think it will cause cavitation? one guy on SAU got Cavitation with this same setup, however his 044 was mounted only like 1-2 feet away from his 044 in the truck, where mine will be in the engine bay.

How do people setup up dual walbros as far as the fuel lines are connected, at the moment I don't feel like hassling with my fuel rail and so forth, they just Y the two lines together before the inlet on the rail?

[Darius]

If you get me the two pump curves, I'll take a look at it for you. It is possible to get cavitation in the walbro if the 044 pulls too much flow and runs off the right end of the walbro curve. It surely would cavitate then and quickly wear out the pump until it failed. If that is the case, it is not even worth running the walbro at all.

The placement of the 044 shouldn't have a huge effect on the walbro unless there is a lot of pressure loss between the two. If that is the case, the 044 would flow less and draw less on the walbro, which might keep it from running off its curve. That is probably an inaccurate assumption.

A quick fix would be to drop the voltage going to the 044 so it didn't pull as much flow through the walbro. (resistor)

[Shocker]

Heres their pump curves on the same graph...



thanks Darius, I'm thinking the 044 will end up overtaking the 255 and causing cavitation... I might end up just doing a dual walbro all I need to see is someones fuel rail setup on how they have them comming together.

If Riggs was making his dual setup at 650rwhp on e85 they should be good for 750-800 if properly powered on gas... which is well above what I need.

[gawdzilla]

i'm not a fan of walbro cuz they just seem cheap (price and quality). i've heard stories of success and failure, so i dunno. running a dual pump setup is riskier too cuz you usually don't know when one fails until it's too late. Riggs dynos a lot and luckily it failed on the dyno when he was getting tuned. If he was dragging and his tuner wasn't there watching i'm pretty sure bad things would've happened.

if i ran a dual setup i'd get dual 044's and be done with it. single walbro, ok maybe. inline walbro, maybe. just my opinions though

[Shocker]

You know I was talking to my buddy at school about this 044 setup I have drawn above, he will be running the same exact setup in his GLI with a 30r. He says tons of Vdub guys run it exactly how I have it above with zero issues. I guess its ment to be ran this way.

So I most likely will got that route and try it or, do a dual setup I spent a good amount of the day researching. I'm going to research the 044 with walbro lift on vwvortex see what more I can find out.

Supra guys love walbro's it seems so many are running dual or 3 of them from their hanger, Titan freaking sells a bracket for like 350 bucks to do a dual wally setup lol.

[rustbucket]

Keep us updated, I'm interested in runing the same setup.

[Shocker]

Well I've been convinced that my initial setup will work, I just got done reading multiple treads on VWvortex with guys running an intank walbro/stock pump then an 044 inline off the same feed line from the tank with zero issues and huge HP capabilities.

However I have came up with a very cheap twin walbro setup that will cost me about $120 dollars... since I already own one pump...

So its looking like either $250-260 for the 044 and fittings

or around $120 for another walbro....

I'll have to sleep on it I suppose. Either way I'll post results and most likely a write up when I start doing which ever I decide.

Motors supposed to be done this week. transmission hopefully Saturday with fresh brass and new seals.

[Cjmartz2k]

I am following your other thread on SAU with interest. It's funny, as soon as I started reading, I was like "this guy is american" but they needed to be told.

I'm in about the same boat as you. Right now I'm single Walbro, and I'm already well past what the aussie guys are saying they are safe to run HP wise. I trying to decide between another Walbro and a Bosch 040. Can you post up the links where you are finding these so cheap?

[Shocker]

Yeah they had no idea I was American lol. They are friendly guys though.

Its the bosch 044 not the 040, that on is intank the 044 is inline. You should watch out for fakes as the Chinese make replica's in bosh boxing EXACTLY like the real 044, the fakes have a almost mirror like finish on their bodies, the standard 044's are more dhull.

This guy is legit for the 044. http://www.jayracing.com/index..._id=1

then ebizzle for the 255.. plus the rest of my DIY parts if I do a dual intank....

Currently I'm leaning more towards the inline 044, I'm gonna check out my engine bay more this weekend see how much room and so forth there is to place it.

[Shocker]

I'm still kicking around this fuel pump setup here.

You guys know what the housing for the fuel pump is made out of? Is it weldable at the top if anyone knows?

[Carl H]

housing on the 044 appears to be aluminum... has threaded fittings on the top, metric but i forget the pitch.

[Shocker]

housing on the 044 appears to be aluminum... has threaded fittings on the top, metric but i forget the pitch.

yeah, I meant the actual housing for the pump itself that its attached to, like that intank assembly, that the fuel lines come up and out of.

[Shocker]

this what what I'm talking about.

I'm talking to the top of the bracket where the fuel lines come out of the sump. In this picture... its not mine.



Reason asking is its magnetic I tested that, but it doesn't just look like straight steel it appears to be an alloy. I'm going to be drilling a hole in it, and running some fittings for an inline fuel pump setup. I'd rather have the fittings welded to the head to avoid any gas fumes.

Anyone ever have any experience welding to it? I've got a mig.With steel wire in the roll.

[rbsileighty]

MKIV and 3SI both show good things about the Denso unit... still my favorite (I am running a single) because of the flow and the noise... very quiet

There are some things to save money on and some places you shouldn't... your motor needs fuel, so I'd be reluctant to save ~$100 for the $ of damages that could be incurred from being thrifty

[gawdzilla]

MKIV and 3SI both show good things about the Denso unit... still my favorite (I am running a single) because of the flow and the noise... very quiet

There are some things to save money on and some places you shouldn't... your motor needs fuel, so I'd be reluctant to save ~$100 for the $ of damages that could be incurred from being thrifty

the Denso is a nice piece for sure. OEM reliability and quietness. However, if you want more than about 450 whp the Denso will drop fuel pressure. I had mine hard wired to keep the volts up but it pulls too many amps for the stock wiring from the lid to the pump itself. If you read the reviews/tests everyone says its a great pump if you can supply the voltage and current, which is easier said than done. That is why a lot of ppl can push more whp out of the walbros despite the flow #s. The walbros require less current

[Shocker]

MKIV and 3SI both show good things about the Denso unit... still my favorite (I am running a single) because of the flow and the noise... very quiet

There are some things to save money on and some places you shouldn't... your motor needs fuel, so I'd be reluctant to save ~$100 for the $ of damages that could be incurred from being thrifty

Thats why I'm changing my setup. I plan to leave the intank walbro. Keep that line running all the way up to the front of the car.

Then drill a hole sort of like this...

Run a fitting like that, have a line running to the base of my sump, tied into my bracket so it picks up fuel at the very bottom of that tank. Run that line up through the hole I (will) drill, have it go through an inline fuel filter, then into my bosch 044 pump, send a line off of that 044 all the way to the engine bay where the 255's line is, run a Y block so they come together, fuel filter once more, then into the rail.

That way the pumps will be on separate lines until the fuel rail.

heres my once again **** dwg....


Modified by Shocker at 2:31 PM 3/20/2008

[DETurbine]

I know most don't like Walbro, but in my preferance they are a decent pump. I am not sure how much power you plan on running, but if you aren't planning on making any more then 550hp, then a single walbro is going to do the job. At a 12 volt supply a 255 lph pump is capable of running a MAX of about 644hp and cranking it up to 14 volts is capable of 773hp. Now you should never run a pump to it's maximum cycle, but like I said, you could run a reliable 500-550hp out of a 255 lph pump with the stock 5/16 feed and return lines that the 240sx has.

The dual walbro setup isn't the smartest decision in my opinion. You should always run a single pump setup rather then a dual pump setup. The risk of one pump going bad and leaning out is not worth it.

[Shocker]

Thanks for the response, I'll be making about that... well should be. Over that amount on race gas. Personally I'm just going to do the dual setup, I'd hate to get down there and run out of fuel and not be able to finish my tune.

Honestly whats the difference if theres one big pump or two little pumps? Either fails both will be known lol, Especially since I 've got a big wideband staring me right in the face.

[DETurbine]

If a fuel pump failure were to occur on a single pump setup no fuel is delivered and no harm is done to the engine. You can normally diagnose the problem quickly and easily replace the pump. On a dual pump setup, you may have only half or a third of your total fuel supply available. You may know nothing is wrong until it is to late and you are not just replacing your pump, but your pistons as well.

Another thing to consider is that most people actually think if you run a dual walbro setup that it doubles the amount of fuel, but at best you might get 1.65 times the flow (421lhp) and the only way to accomplish that is if you were to have both pumps in a parallel configuration joining them with a Y adapter, two -6 lines transitioning into -8 lines.I have seen people run dual walbro's with success, but then again I have seen others that have not. A close friend has come close to blowing his freshly built motor with his dual walbro setup and I wouldn't want to take that chance

[Shocker]

I'm not going to be running dual walbro's..... one in tank walbro, and on inline 044. I'm working on this today, and most likely will do a write up for it.

Problem is ONE big pump, is that it would be in my hatch. This car is pretty much a daily for me when it runs, I don't want to be going on trips to places and smashing my fuel pump when I put items back there, or having to listen to the loud *** thing while just driving from place it place. If this was a race car sure, however it is not.

If one pump were to fail on my current setup, it would be maxing the other out, but still providing about enough fuel, I'd most likely hear the sound difference, see my a/f's are a slight bit rich and shut it down.

[gawdzilla]

if i were in your situation i'd run the 044 in tank. harder to fit but in the end will be less headache. that's the setup carl is running.

[Shocker]

if i were in your situation i'd run the 044 in tank. harder to fit but in the end will be less headache. that's the setup carl is running.

To late I'm already half way done with my new setup it was pretty cake. I'll do a write up for all to see sometime this weekend early next week, and get some calcs as well to see what it will actually flow.