1G Questions on external fuel pump install

[Kapok6]

Lettuce discuss an external fuel pump install on a 1G AWD. I have a few questions I am looking at a magnafuel MP 4301.

1.) I was going to use the stock hanger assembly, but just put an 8an bulkhead fitting in it and some kind of pickup tube with a sock. Does anyone with EXPERIENCE have a suggestion on what kind of tube to use as the pickup tube? I.E. SS, Aluminum, etc? Any advice on a filter/sock for the end of the pickup tube? I figure the measurement par should be easy. Just make sure the tube ends where the stock pump inlet would end.

2.) Mounting location. Being that it's external, I am guessing I can mount it anywhere. Is there a preferred location? My engine bay is kind of crammed, so I was thinking of putting it under the car near the back; maybe trying to mount it somewhere around where the rear seats are located and the body kind of slopes up. That would leave me those grommets right there to route the current power line(s).

3.) Would running the feed line off the drain plug be a better idea? Or just leave the drain plug alone and work on running it as mentioned above?

@bastarddsm @biglady112 @donniekak

 

[biglady112]

I am a big fan of sumping stock tank. The only problems a have run into with doing it without much thought is fuel sloshing issues. On our mirage we just welded fittings to the back of the tank and ran it. It worked fine, it just starved the pump much more than I would have liked.

I do not like trying to siphon uphill and would not build something off of the hangar housing not let my friends do it. Not to mention how many bends, angles and fittings you would need just to try to get it to the pump/filter.

Mount the pump where it is easy to work on and can be fed fuel easily (gravity? )

There is only one problem with welding/finding a fitting to the drain. The fitting coming off the bottom will have poor ground clearance. It would certainly work. The other smaller issue is fuel slosh will be an issue on any turns sending fuel away from the feed.

My vote is sump the stock tank.

 

[GST with PSI]

Have you considered a surge tank? There are quite a few tanks available with integrated pumps. Simply mount the tank under the car somewhere, and use your in-tank pump as a lift pump. The lift pump doesn't have to ridiculous, since it's operating under low pressure.

There are some inexpensive tanks on Ebay that integrate the Bosch 044 trype pumps. On the other end of the spectrum, there are some really nice (but pricey) units from DW, Nuke, Radium engineering, etc. For what you'd pay for a MagnaFuel pump, you're half way there for some of the nicer surge tank setups.

You're running an in-tank Walbro 450, yeah?

 

[Kapok6]

Was on a 450 and stock lines. Ran out of fuel with the 82hta pushed to it's max with this motors rich fuel requirements. So I went 2150's, 8an feed lines, and a duel pump setup with a walbro 450 and an aeromotive 340. Car ran good for the last few weeks. Then this friday, I launched it...hard and the car went stupid lean and broke up badly, rpms fell, etc. Pull into parking lot and car idles fine. The car drives fine. AFR's are good. There are literally NO signs of any issues until I get into boost, then car starts leaning out. No idea WTF is going on. So I start checking fuel pumps. Car off, I manually power the 450. It pressurizes the whole system fine. So I shut it off, let pressure die down and power the 340 only. Pressurizes the whole system fine. So I plug them both in as they were, start the car, and take power off the 340 so only the 450 runs. Car doesn't miss a beat idling. So I put power back to the 340, take power OFF the 450, car loses pressure and dies almost immediately. Wash, rinse, repeat, same thing. 340 for whatever reason will not even allow the car to maintain pressure to idle.

The more I think about it, the more i'd rather just shy away from the whole 2 pump thing. Kind of going back to Steve's point in a previous thread about one of the downfalls of relying on 2 pumps.

That being said, even though I have been into DSM's since 2004, I have never really messed with fuel system stuff too much other than injectors and pumps as the 450 got me pretty darn far. That being said, please forgive me for the stupid questions about to ensue.

1.) Sumping. Is sumping in this context referring to running the feed line off the drain? I'd rather not do that as I still weekend warrior this thing. 100mi cruises and races in mexico on nice weekends and getting groceries (literally) sometimes during the week. The Magnafuel said self priming, so I assumed it should be fine putting it anywhere and feeding it from anywhere. I mean, it'd be doing the same work even if I ran the feed off the drain if I have the pump mounted higher than the drain anyway, wouldn't it?

2.) Surge tank. What exactly is that, how does it work/what's it's purpose, and how "hard" is it to install?

 

[bastarddsm]

If you find my build thread I have pictures of what I have done. 1/2" .035" wall stainless welded to a steel bulkhead fitting, -10 into a t, into dual 255's. Mounted by the tank.

 

[91talonts1]

I'm running a magnafuel pump for the same reason you seem to be looking at one. Torched a motor bad when one pump in a dual setup failed at WOT and it went way lean. That plus the simplicity and they're serviceable.

I can't comment on what to do with a 1g tank, I have a 2g and a jaz cell. I have mine mounted about 4 inches to the right of the cell about 1 1/2 inches above the sump. It primes itself no problems.

 

[Kapok6]

So I just did some quick research on surge tanks. I believe I see their purpose. That being said though, doesn't that still have you relying on multiple pumps? I/E, if the pump in the main tank dies, wouldn't the surge tank empty out? If that's not the case, and the pump(s) in the surge tank can still siphon fuel from the main tank through the dead pump, again, to move the amount of fuel I need, i'd have to have a surge tank with multiple pumps, so again, back to relying on multiple pumps.

 

[91talonts1]

Yes if the small pump fails in the main tank, the surge tank will go dry. But you're only relying on the big pump fed from the surge tank for all your engine fueling. The pump in the main tank is only there to fill the surge, if the surge runs dry the engine shuts off. This is what I'm familiar with at least.

This would be beneficial as you just keep your factory tank and pump as is. Install the surge tank and main pump separately. I went the magnafuel route instead due to space constraints for a surge setup and the factory 2g AWD gas tank sucks. I was looking at spending alot more on the surge setup than just the MP anyway.

 

[Kapok6]

Yes if the small pump fails in the main tank, the surge tank will go dry. But you're only relying on the big pump fed from the surge tank for all your engine fueling. The pump in the main tank is only there to fill the surge, if the surge runs dry the engine shuts off. This is what I'm familiar with at least.

This would be beneficial as you just keep your factory tank and pump as is. Install the surge tank and main pump separately. I went the magnafuel route instead due to space constraints for a surge setup and the factory 2g AWD gas tank sucks. I was looking at spending alot more on the surge setup than just the MP anyway.

That's how i'm looking at it. I mean, a good surge tank without pumps is more than this Magna pump, then I have to find out where to put it, and I have to have multiple pumps in the surge tank to supply the fuel I need anyway. If one External pump will work, it really seems like the war to go, especially since it's 8an in/out and I already have an 8an feed line from tank to rail right now, so most of what I need is already there.

Do you have any pics of how/where you mounted the Magna pump?

 

[91talonts1]

That's how I was looking at it. The price of a Radium surge tank or the equivalent is ridiculous. Then the added plumbing, wiring and mounting hassle of the extra components, and you still end up either needing a big primary like the magnafuel or running more than one. I figure the magnafuel being rebuildable should last forever and it's a single pump that I'll never need to upgrade again. I have a little over 2 years of ethanol use on it, doing pretty much what you describe using your car for.

Not easy to get pics of it without putting the car on a lift, but I had this one on my phone. It's just mounted to a piece of 1/4 inch aluminum plate that's bolted across the fuel cell supports.

You must be logged in to view this image or video.

 

[biglady112]

Here are some quick pictures I found doing a Google search of a dumped stock tank. One may not be a dsm, the rest are. Pretty easy deal and works like a champ.

Surge tanks are for mechanical fuel pumps. Awfully redundant to run a surge tank with an electric pump unless you are a road race car with slosh issues. You are really limited by your imagination here. Don't be afraid to weld something and modify your car to get your desires results. Make a smart choice the first time. Don't leave yourself wishing you had done more later. If you cannot or don't weld stuff, plenty of competent people out there that at willing to help.

 

[Kapok6]

Based on those pics, sumping won't work for what I use this car for. Lot of driving, speed bumps, uneven driveways, etc. On a drag car, sure. You are either on a trailer or a nice flat track.

I also notice in that one pic, the pump, wherever it may be, is definitely higher than the inlet on the tank side of the line, so it's still siphoning.

 

[Kapok6]

Most of my imagination right now is being spent trying to figure out how to build the actual fuel pickup tube.

 

[91talonts1]

Ground clearance on those 1g sumps isn't as bad as they look in those pics. I've seen a couple up close and they sit about level with a normal sized muffler. That being said, big difference in banging a muffler on the pavement vs a fuel tank.

 

[Kapok6]

Ground clearance on those 1g sumps isn't as bad as they look in those pics. I've seen a couple up close and they sit about level with a normal sized muffler. That being said, big difference in banging a muffler on the pavement vs a fuel tank.

Yeah, that's why I am more turned off by that idea on my application the more I think of it. The last thing I need it hitting the tank/lines/fittings on something.

 

[GST with PSI]

That's how i'm looking at it. I mean, a good surge tank without pumps is more than this Magna pump, then I have to find out where to put it, and I have to have multiple pumps in the surge tank to supply the fuel I need anyway. If one External pump will work, it really seems like the war to go, especially since it's 8an in/out and I already have an 8an feed line from tank to rail right now, so most of what I need is already there.

Your limiting factor is going to be the stock fuel tank. So long as you retain the stock tank, you're going to be affected by one issue or another.

Ideally, if you run an external fuel pump, you want to be running it in conjunction with a fuel cell that has a built in sump to feed the external pump. Without a fuel cell, you only have a few options if you keep the stock fuel tank:

1) Modify the stock tank and add a sump to feed the external pump (like in the pics biglady112 posted).

2) Run a lift pump in the stock tank to feed the external pump. This works best with a surge tank between the lift and external pumps. BTW, surge tanks are NOT just for mechanical fuel pumps. People have been using them with electric pumps forever.

3) Fab a pickup into the stock tank.

Now depending on application, options 1 and 3 will still leave you with potential fuel slosh/starvation issues. Option 2 will remedy this, but will rely on multiple pumps, so chances of failure increase. So, it's all about give and take, and what setup will work best for your build.

Personally, I'd go (and personally did go) with a surge tank setup. There are a lot of tank options to choose from in various price ranges, so cost can be mitigated: http://www.dsmtuners.com/threads/gstwithpsis-galant-vr4-1837-2000.482807/page-12#post-153636124

Also, good information about how the system is typically configured and works: http://www.nukeperformance.com/technical-info/flow-chart-faq/

 

[Kapok6]

When I spoke to the tech at magnafuel, he stated it shouldn't be an issue to run the pump with a draw tube(s) as long as the pump was within 2-3ft of the draw tubes. He said it should have no issue priming. He did suggest either running a 10an sized draw tube, or using my current double pumper hanger with two 6an bulkheads and just putting draw tubes on each one of those, feeding into a y fitting, then 10an from the y fitting to the pump inlet.

He also recommended 100-75 micron socks for the tubes.

I don't see how sloshing in this setup could be any worse than it would be with in tank pumps since the tubes/filters will be right where the inlet(s) are for in tank pumps...

 

[GST with PSI]

I don't see how sloshing in this setup could be any worse than it would be with in tank pumps since the tubes/filters will be right where the inlet(s) are for in tank pumps...

It shouldn't be any worse. If you're getting sloshing with a pump, you'll likely get sloshing with a draw tube as well.

 

[bastarddsm]

If you want a pickup made, just ask . Mines been in my car since 2012, and working great. Proven for 140mph traps with 2 walbro 255's, and it was rich as f*** too.

Everyone I know that runs a magnafuel ended up dumping it for a pair of 044's. If your that worried about a pump dying you could probably rig up a detection setup using a set of check valves and pressure switches. Or, and arduino and a few pressure sensors, watch boost and FP, if they are not within a certain range of each other, and wb shows lean, an alert goes off.

Still though I've been running dual pumps since 2012, and had one die in 2014, it was instantly noticeable, and I didn't hurt the engine.

Furthermore if your that worried about it just replace them yearly, they are cheap enough, and a use one sells for 1/2 price of new.

 

[bastarddsm]

Just noticed the sloshing comment. Pickup, and 2 externals, and I have done low 1.5's and no starvation issues. You have to be on E for my car to starve the pumps.

I'll log fuel pressure for a couple passes this spring to see how it's really doing.

 

[Kapok6]

If you want a pickup made, just ask . Mines been in my car since 2012, and working great. Proven for 140mph traps with 2 walbro 255's, and it was rich as f*** too.

Everyone I know that runs a magnafuel ended up dumping it for a pair of 044's. If your that worried about a pump dying you could probably rig up a detection setup using a set of check valves and pressure switches. Or, and arduino and a few pressure sensors, watch boost and FP, if they are not within a certain range of each other, and wb shows lean, an alert goes off.

Still though I've been running dual pumps since 2012, and had one die in 2014, it was instantly noticeable, and I didn't hurt the engine.

Furthermore if your that worried about it just replace them yearly, they are cheap enough, and a use one sells for 1/2 price of new.

Mind sharing how you did it? I was just going to do a -10an bulkhead through a stock assembly threaded into an aluminum tube that ends where the stock pump would end in the tank. A filter/sock is what i'm thinking I may have some difficulty with.

Thoughts?

 

[bastarddsm]

I wouldn't use aluminum, unless it's annodized. Stainless is what I used. I bent a 90* on mine and pointed it towards the back. IIRC I have a -8, and a -10 would be a very very tight squeeze. I made a stainless sock by spot weldeing it together. There's pictures on here of it.

 

[Kapok6]

What's the issue with aluminum? Our fuel rails are aluminum.

 

[91talonts1]

Bare aluminum isn't ethanol compatible.

 

[Kapok6]

What's inside our fuel rails?