ttg35fort

iTrader: (2)

***** MODERATORS, PLEASE LEAVE THIS IN THE F/I SECTION AS IT IS MOST LIKELY ONLY TO BE USED BY THOSE WITH FORCED INDUCTION ******

I'm looking into have a custom external swirl/surge tank fabricated in 6063 Aluminum, 0.12" wall thickness, with AN-10 male fittings. It will also have internal baffles to mitigate fuel slosh on a road course. We have not yet settled on the final dimensions, but it will likely hold about 1.6L of fuel, and fit behind and above the rear axle on G35s and 350Zs.

Is anyone else interested in this? If so, post here or PM me. I may have extras made up to get a quantity discount, depending on the response. Price is likely to around $300 each. These also can be powder coated at an extra cost (I'm guessing somewhere around $50).

With this swirl/surge tank, you can run any external fuel pump you want. I'm looking at using two in-line Walbro 255 LPH fuel pumps (one for each fuel rail) or a single Aeromotive A1000 fuel pump, which is good for up to 1000 hp on a FI fuel injected car. Here is the flow graph on the A1000:

http://www.aeromotiveinc.com/prod_im...64-2-large.jpg

The Aeromotive A1000 flows about 780 lb/hr at 50 psi and 13.5 V, which is around 480 LPH.

Summit racing sells the Aeromotive A1000 fuel pump (P/N AEI-11101) for $315.95. Inline Walbros can be found on the Internet for about $110 - $120 each.

JETPILOT

iTrader: (51)

I would be interested if this is a fix to fuel starvation uder sustained lateral G. But isn't the problem still going to be the in tank Walbro running dry? So instead of not being able to suply the motor it won't be able to supply the surge tank. I'd like to see pics of it and how it will be plumbed. Will it have mounting brackets?

AAM sells one, but it is plumbed wrong. They have the fuel return going back to the fuel tank when the fuel return should go back to the surge tank. Their surge tank is also $1200. Way too expensive.

djtimodj

The swirl tank should last long enough to supply the motor in the turns as it should top up with fuel from the in tank walbro down the straights. Will work ok as long as you dont like driving in circles in 3rd gear for 30mins!! lol..

ttg35fort

iTrader: (2)

With the final dimensions, it holds about 1.6 L of fuel and has internal baffles. If the Walbro runs dry during a high G turn or under hard acceleration, the 1.6 L of fuel in the surge tank should be more than adequate to sustain fuel pressure until the Walbro begins picking up the fuel again. Moreover, the fuel pressure between the Walbro and the surge tank is fairly low, so the Walbro can quickly refil the tank.

I am mounting the surge tank on the plate that is behind and above the rear differential, between the rear most GTSpec Brace and the exhaust brackets. That plate is not perfectly smooth, so rather than putting tabs on the surge tank itself, we are going to use U-brackets to hold it in place. I'll take pictures when it is in.



Also, some specifications have changed. Originally I was going to try to make it hold 2 L of fuel, but the surge tank would have been a little large and hard to fit. Also, after researching the strength of aluminum, 0.12" wall thickness will be adequate. Also, it looks like these changes will save some money. Right now it looks like it will be around $300.

I spoke with a number of different people about whether to run the fuel return to the surge tank or back to the fuel tank. Those I spoke with all recommended running the fuel return back to the fuel tank. Nonetheless, if you want to run the fuel return to the surge tank, the fabricator can install an extra bung to receive the fuel return.

JETPILOT

iTrader: (51)

I'd like to see it when it's done. If it works and it's done relatively soon I'm in.

TrackPack

iTrader: (1)

The ONLY proper way to do it is to return to the swirl pot/surge tank and then the over flow from the surge tank would go back to the gas tank if the surge tank is full. Something like my SX pump would put a hurting on the surge tank on a long sweeper if the intank went dry and the fuel wasnt returning to the surge tank...

We've made lots of these, the concept is very simple. Anyone who directly returns to the tank without going to the surge tank first is efficiently increasing the fill time during the intank dry spell. Essentially making the surge tank almost useless. I dont know if I'm getting my point across, havent slept in 24hrs, but if the intank isnt refilling and the external is drawing......with out having the excess fuel refilling the surge tank, makes it substantially less beneficial to you, less run time off of same volume tank.

Hope some of that made some sense...... good luck with the project, hope the build it right for you.

QuadCam

iTrader: (8)

question for you guys..............

if you are attaching the fuel return line to the surge tank.....and then hooking up the "overflow" line to then return the fuel to the gas tank. Does that affect the efficiency of the "siphon jet" that pulls fuel from the driver's side saddle into the passenger side saddle? to simplify my question, is there enough velocity on the overflow line to make the siphon jet work as it was designed? If not, you won't effectively take advantage of the full fuel capacity of the 20 gallon tank!

TrackPack

iTrader: (1)

But of course, think of it this way, the surge tank and the external pump are just cycling fuel round and round full time. while being fed by the factory/walbro pump, which is pushing 90%of its volume to the return in the tank aslong as the surge tank isnt being pumped dry. And you would b helping it being pumped dry by not returning to it. Imagine the surge tank as your only gas tank, now imagine the motor at idle drawing and returning to that tank, it would take a long time to run out of fuel right? well now incorporate the intank into the mix forcing more fuel into the surge to make sure it is full to the brim, well it has no were to go but to return to the intank siphone under the exact same pressure/volume if not more that you would have recived in an unmodified fuel system.

I'll try my best to explain his but its difficult without diagrams.

QuadCam

iTrader: (8)

trackpack...makes sense. I just wasn't sure if it really does have the same volume/velocity/pressure to work the siphon jet as designed.

secondly, do you need to match the free flow rate of the walbro to the "under pressure" flow rate of the secondary pump. IIRC, AAM used the Bosch 044 pump on their surge tank setup. the Bosch (at 3 Bar of fuel pressure) flows almost the identical amount that a Walbro 255 flows in free flow. If you are using an A1000 (or similar Cartech, SX, etc.), will that pump drain the surge tank faster than you can fill it (if you are maxing out the fuel flow of the A1000)??? if the 2 pumps were directly connected inline of eachother, the big A1000 would be pulling on the walbro and wouldn't be a problem. But with the surge can in between the 2 pumps, the A1000 could potentially drain the tank faster than the walbro could supply it and then the pump would cavitate. Of course, this would only happen if you were making a 1000+ HP and your engine was sucking every ounce of fuel that the A1000 could supply.

TrackPack

iTrader: (1)

definitely does not have to be matched in flow rates, heck I think the walbro is over kill as a supply pump. generally when we design a surge tank set up we *try* to make sure that if the intank ever quit or went dry under WOT, we would still have 30 seconds of Bsfc/max hp fueling, Sooooooo in a 1000whp application your motor would be consuming 6000cc's of fuel a minute so you would need a 3000cc = 3 liter surge tank reserve capacity to ensure that you have 30sec's of *max hp fueling* Buuuuut..... thats kinda over kill for most applications, because even at WOT your not at your max bsfc 100% of the time, plus 30 seconds of WOT 1000wheel hp is a f*ckin' death wish! And thats 30 secs of NO walbro assistants. So if the intank was helping you would never ever ever run out of fuel in that 1000whp car.

That example is kinda hardcore texas mile style, so for a street aplication just figure out how much power you want, how long you want of a safety net with the intank not assisting, and that will give you the general size of tank you need. Unlike others that just provide you 400cc tank that is worthless bythe way, you now know how it works! Dont get suckered into buying an extremely under engineered tank setup, they are out there!.

ttg35fort

iTrader: (2)

What you are saying makes sense. I originally had the fuel return going to the surge tank, but then a couple of people were concerned about how this might affect fuel pressure regulation.

Nonethless, the difference in fabrication is merely adding one additional bung. I'm leaning towards adding the additional bung and trying it out with the fuel return going into the surge tank. If we run into fuel pressure regulation problems, I can always cap off that bung and re-route the fuel return back to the fuel tank.

TrackPack

iTrader: (1)

Ohh and for what its worth, OP I wouldnt run dual walbros or a aromotive a1000, alot of my friends do run the a1000 and I have seen them fail, plus they are noisy as hell! For a duel pump set up I would run twin 044's for the reliability(and thee 1400hp worth of fuel lol) Orrrrr if you like big singles nothing beats the SX in my books, its soooo quiet in comparison to the A1000, and edges it out in flow too! plus "essex" makes the pumps on stealth bombers, and other aircraft and marine apps, and they handle alcohol fine. I would think they know how to make a good pump. No comparison in my book.

TrackPack

iTrader: (1)

make sure the "overflow" line can efficiently handle the return volume and you wont run into any reg. issues you already wouldnt have seen with the factory siphon restriction.

cheers.

ttg35fort

iTrader: (2)

All the fittings are AN-10. That should be adequate.

ttg35fort

iTrader: (2)

Too late. I already have the Aeromotive A1000. I'm mounting it outside the car. But if it turns out to still be too noisy, I'll sell it on Ebay and get something else. I'll look into the essex fuel pump.

Fluid1

iTrader: (19)

In for the long haul....interested to see the progress.

QuadCam

iTrader: (8)

TrackpAck, do you remember the old Cartech pumps? I think they were rebranded SX pumps.....before SX got into the car market (back in the early to mid 90s). I had one on a MUstang Cobra, and it was awesome. not too noisy; couldn't hear it over my exhaust.

The new SX pumps don't look anything like the current ones. the old ones looked like the current aeromotive a1000.

ttg35fort

iTrader: (2)

Has anyone else used the SX fuel pumps? Any opinions?

Any other opinions RE the noise of the A1000? Does mounting the A1000 with rubber grommets help?

ttg35fort

iTrader: (2)

I spoke with Roger at Japtrix. We are going to run the fuel return back to the surge tank, and then run the overflow from the surge tank back to the intake fuel pump. Roger does not think there will be a fuel pressure regulation problem.

Thank you TrackPack for the advice!!! I've learned it's better to listen to people who have actually done something rather than people merely speculating about it!!!

Here is a drawing of the Surge/Swirl Tank installation:

rrmedicx

iTrader: (54)

The diagram above is exactly how I have mine setup. I found a sweet deal on a used AAM kit without any plumbing and fabricated my own SS lines. I used -6an from the walbro to feed the swirl tank/Bosch pump and -8an from the Bosch up to the rails.
I too modified the swirl tank with an additional bung to receive overflow.

In addition, unlike the original AAM set-up I relocated the main feed and overflow return (feed #2) to the ends of the tank rather than feeding directly above the -8an line leading to the Bosch. Reason is to avoid pulling any bubbles into the Bosch.

My Theory: When you feed the swirl tank the fuel will naturally make some turbulence and bubbles which you don't want being run up to the rails.

Just my .02