WHich pump and which regulator do you guys recommend for a 2.0 turbo subie? Also, I saw a gas tank well that attaches to a standard tank on outbacks website. Is this something that is needed, or just an added precaution? Thanks again...

fuel pump... bosch # 0 580 254 982

On the regulator, you can use the stock Subaru one, as long as it's a turbo one.

Otherwise, you can use an Aeromotive. Those can be had at Summitracing.com

my dad runs exactally what tripod said with no problems just make sure you run a pre and post fuel filter the only trouble we have had is keeping the injectors clean....Mike

thanks guys...what about the well?

I used the sump Outback sells on my spun alm. tank. It works very well. It just needs to be welded to the bottom of the orig. tank. Prior to welding a few holes need to be drilled in the bottom of the tank. The bungs are for feed and return. I used -8 or -10 to feed and -8 for my return. The feed was gravity fed to my elec. fuel pump. Hope this helps.

i have that whole set up from outback...works great...jon knows his s***...and a good guy

is the well a necessity?

Yes,an efi system does not tollerate air in the system as well a carburated engine,even though it is a lot of work, put it on.The last thing you want is a lean cylinder under boost.

Midpinto, i have run my 2.5 subie last season without a sumpon the tank with no problems whatsoever. My buddy has a turbo mitsubishi with no sump as well and has not had any problems for the last three seasons, however, i would strongly suggest the pre and post filters in the systems.

Thanks for the replies....I had never even heard of these until I was looking on the outback site. I was under the assumption that if they were a requirement I would have read something about them on the board. I did not see the price listed on outback's site though...anyone know what they cost?

Sumps have come up a number of times on the board. With a carb they're not needed (but won't hurt) but with EFI it's a VERY VERY Good idea espically in something like a rail that will be romped off road at odd angles.

With a carb you have float bowls that hold a small amount of fuel so even if your fuel pump sucks air for a few seconds you'll still have fuel going into the motor. With EFI if your pump sucks air you'll get air out the injectors instead of fuel and the computer will have no way of knowing - result...lean cylinder.

A lean cylinder under load can end your trip in a hurry - espically if you're running boost.

You don't need to do a sump on your tank though. You can do a "surge tank" instead which is a small (approx 1qt.) tank fed by a high volume low pressure pump from your main tank that assures your high pressure EFI pump will always have fuel availalbe. Do a search on here for "Surge tank" and you'll find a number of discussions and explanations.

Aermotive 13109 is the one you want

The sump costs $50.
Sure you can run without one by generally keeping the tank better than half full, which most people do. it's when the tank is low that is the problem. If you had an 11 gallon round tank and had three gallons in it, in a hard bowl/turn or driving at a 30' angle you would probably suck air--not good. With a high output motor under heavy boost it could take only seconds for engine damage. Most people think that a huge hole is cut out of the bottom of the tank, to the contrary we just cover the original outlet and drill a couple of .125" vent holes in the upper corners. The sump is about 2 quarts. The fuel that comes down into the sump cannot leave under any cornering. With this setup you can drive just as hard with 2 quarts of gas as when you have 10 gallons. It's also a great way to "get" the return port on you tank because most round tanks were designed for a single outlet.

p.s. it is a very bad idea to "tee" the supply and return to the original outlet

Sump's in stock

hmm, I tried to spell "kcoctep" backwards but it automatically changes the word to "petdork" I changed it to "outlet" maybe I don't know the spelling of that word.

John

I got a surge tank from spooner and it has a fitting for EFI return and another one for a return from the surge tank to the main tank. I think it was intended to be mounted above the main tank, be fed by a low pressure pump, and have the return to main tank work off of gravity.

My question is: Can I mount the surge tank below the main tank, gravity feed the fuel from main to surge and return into the surge only (no return to main tank and no low pressure pump from main to surge)?

This sounds like it will work similar to the Outback sump set up, but I wasn't sure how returning fuel to an already full surge tank will work.

Thanks for the help

I am running the surge(accumulator) tank on mine. I have the 2.5 Subaru and the only prob I have a had was the weld on the tank. I had it rewelded and no troubles since.

p.s. it is a very bad idea to "tee" the supply and return to the original outlet icon_mad.gif



Why is that?
air bubbles maybe?

You can mount it lower than the main tank but I wouldn't rely on gravity alone to feed it unless you plan on only driving on the flats. We do a lot of off center stuff and gravity only works straight up and down

Plus you'll still need to have a return to the main tank. You don't need a pump on that line - it's more of an overflow to let excess fuel return to the main tank if the sump overfills. Some people run their return straight to the main tank from the fuel rail so the hot fuel won't get circulated right back to the engine - others return to the sump and rely on the flow between the main tank and the sump to assure cool fuel to the rail.

I hear what your saying, but the gravity scenario doesn't seem much different than Outback's sump set up. Only difference being a very short piece of hose connecting the two tanks ( I have not actually seen a picture of John's sump). To me, it seems that gravity is more reliable than a second pump? I thought the idea of having a sump/surge tank is to maintain a continuous supply of fuel when driving on the off center stuff, and letting it refill when conditions allow. I'm interested in learning more about this.

Also, will a return from the surge to the main tank work without a pump even if the main tank is mounted above the surge?

Thanks for all the good info.

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Some people run their return straight to the main tank from the fuel rail so the hot fuel won't get circulated right back to the engine - others return to the sump and rely on the flow between the main tank and the sump to assure cool fuel to the rail.
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went ahead and ordered the sump from outback....got here the next day, I was impressed. Thanks John!

Remember to "Not" cut out the bottom of the tank but to just drill 4 small vent holes (about 1/8") in the corners. this allows the sump to fill all the way.
John

Ok, thanks for the tip....also, when i got home to look at the part I noticed that it's not sealed on the corners. IS this how it'sormally sent, and just requires someone to fill the corners to seal it?

Thanks again John

I think I bought the very first sump John sold. Yes, the corners will need to be welded. BTW, I never had any fuel starvation or any problems at all. I can tell you I had my sump welded before drilling the holes in the corners. I need to drill through the side of the sump into the tank. Not fun. So make sure you drill the holes in the top corners (within the sump footprint) before you have the sump welded.

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Some people run their return straight to the main tank from the fuel rail so the hot fuel won't get circulated right back to the engine - others return to the sump and rely on the flow between the main tank and the sump to assure cool fuel to the rail.
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Hot fuel? Seems like a non-issue. I've never heard anyone concerned about fuel raising in temperature on a rail. I guess it's possible the fuel gains a few degrees, but with the constant flow I doubt it's more than 2 or 3 degrees at best. Fuel that's within the fuel line is usually pretty isolated from sources of heat before entering the injector, and pumping to 50psi shouldn't raise the temp very much for a liquid. I'm I missing something?

I have seen some poor designs where the radiator was in front of the gas tank and blew hot air on it

I also presume that under normal conditions fuel temp is a non issue (+10')
John