i was driving on the interstate with low fuel since i had to wait till payday to fill up. :cry
and as i was taking an onramp at speed, i lost fuel pressure from the fuel sloshing away from the pick up.

had i been boosting that might not have gone well for things, so it got me thinking about some of the "Time Attack" fuel set ups ive seen and how they dealt with this.

now best idea would be internally baffeling the fuel tank or sumping it. but $$$$!! so thats out, and a fuel cell isn't very echanomical for a daily driver.

so i looked at an TIG'ed Aluminium Surge Tank.
now most that ive seen use 2 fuel pumps with pickups on either side of the tank feeding the surge tank then a main pump that fuels the main line.

i currently have ready to go in, an Aeromotive A1000 pump (with the electronic controller) feeding -8AN line to a "Y" block and -6AN to the 8 injectors. (yes i have big plans in mind :evilgrin )

so im trying to figure out how to deal with the 2 pumps, and how to use the existing fuel tank.

Anybody every thought about doing this? or anybody use one on a different platform but similar application principals?
(keep in mind this is just theory at this point too, so i welcome CONSTRUCTIVE discussion)

so we can scrap the 2 inlet pump design and go with a std Walbro 255LPH and the A1000.

because i found this nice helpful bit of math:


"You need to figure out how much fuel you're be using "worse case", and then back out the capacity of the surge tank from the differential flow between the two fuel pumps.

It's sounds harder than it really is - it's just tedious math.

This is just a rough calculation and example...

Popular 550 + 1600 fuel injector combo...
Datalog the pulsewidth at WOT, and this will give you "worse case" fuel consumption.
Just as an example, we'll go 70%...
Approximate fuel flow - 1100 + 3200 = 4300 cc / min x 70% = ~3000 cc / min or about 3 liters per minute.

Walbro 255lph in stock gas tank + Aeromotive A1000:
Walbro ~250lph @ 10psi (should flow slightly more)
A1000 ~300lph @ 45psi (slightly underrated)
So we have a differential of about 50lph or ~ one liter per minute.
Thus, if the A1000 is flowing all of it's fuel into the engine, worse case, the surge tank should drop at a rate of 1 liter per minute.
The Walbro is flowing about 4 liters per minute.

In this case, if at 70% pulsewidth, the surge tank will never empty, cause the Walbro outflows the max fuel going into the engine - 4lpm versus 3lpm.

Now, say the engine requirements are bumped to 5 liters per minute...
We now have a differential of 1 liter per minute between the engine fuel requirements versus the Walbro capacity...
Thus, if the surge tank is approximately 2 liters, this will empty out in about 2 minutes.
Now, 2 minutes of WOT is a LONG time!
Unless you're doing Bonneville LSR runs, this much capcity is more than enough for most road race tracks, where WOT runs are typically 10 to 30 seconds max."

The way I've always understood the surge tank is to have two inlets on top and two outlets, one bottom one top.

So basically the fuel cell feeds through a first pump into the top inlet of the surge tank. Next it flows out the bottom outlet to a second pump and to the engine. Excess pressure is routed back to the surge through another top inlet, and then excess fuel runs out the top outlet to the fuell cell.

This type of setup basically guarantees fuel in the surge tank at all times short of the WOT scenario you described. Kudos on finding the math bits to go along with this, that could prove helpful in the future.

finally got it together! Big props to Mark for the welds! thanks man :thumbsup

(in case people are curious i have one extra UNCUT cylinder left if someone wants to do this too)

what is it and how did i do it?

the total internal volume is just over 2 liters and is all Aluminum.
it has 3 feeds all -6 (one from the return side of the Aeromotive 1:1 FPR, one from the Walboro in-tank pump, and the last is caped but avail for a second Walboro if i need it) and one output that is -10, on the top is the return line to the main fuel tank and other yet to be used taped holes (don't know what for yet but i thought i should put them in)
the AN fittings were TIGed flush with the surface and not taped in so there is no lip on the inside, also less likely to leak.

the final product will be bolted to a plate that has the Aeromotive fuel pump and pre/post filters on it. this will make for a neat and easily mountable package.

when looking for possible tanks i ran across "Oxygen Concentrators" and are basically aluminum cylinders with some threaded fittings on them. they can actually be found in a variety of sizes and since they are "medical grade" welds i figured they were a good piece to start with without having to roll and weld my own cylinders. but others may have access to scrap AL cylinders. mine started out at 5" diameter aprox 2 feet long, pretty large and overkill for a trunk mount volume of close to 5 liters! so i neatly cut off a cap from one end then filled it with 2 liters of water and marked the level, and then cut out that section. then it was off to Mark for welding of the cap, AN fittings, and legs. (summit has these AL male AN weld bungs fairly cheep and in a wide variety of sizes)

now i just have to get it powdercoated and finish the fuel pump plate and were good!

Cool Idea.

Damn, Mark lays down some badass welds.

This is badass Foggy.

Alot of the ideas of yours ive heard, will be amazing when complete!

You should link this over on tuners. Ludachris was discussing how to do this about two weeks ago, but I do not think that he found anyone to weld up a surge tank.

I was going to email you tonight and ask you if you got it and what your thoughts on it where but I finally got on the forum's tonight and those ?'s are already answered.


I've also been meaning to ask, where do you plan on mounting this? I like the idea alot and have been thinking about one for my car since we started talking about this. Mine would be a Drag only application but I like the idea of not dealing with NHRA certs and fuel cells but still being able to feed the big fuel pump.

And for future reference: I'd weld up another one if foggy decides to part with his remaining material.

Originally posted by quicksilver99
I've also been meaning to ask, where do you plan on mounting this? I like the idea a lot and have been thinking about one for my car since we started talking about this. Mine would be a Drag only application but I like the idea of not dealing with NHRA certs and fuel cells but still being able to feed the big fuel pump. And for future reference: I'd weld up another one if foggy decides to part with his remaining material.

this had come up during my planning process.

at first i thought of sumping the stock tank a -10 kit summit has a kit like this. however after looking at the space under the car i couldn't think of a good place to fit a 2-liter surge tank. plus then i had to find a spot for the pump and the filters it was just looking too crowded under the car.
so then i thought of having stuff inboard and still sumping but the required line routing and bulkhead connections made it a nightmare to be going in and out of the car a few times.

then i hit upon an an article in some tuner mag that had a skyline with a crazy fuel setup and used stock fuel pump to feed the surge tank! boom first problem solved! with a little more research i found that its quite common to use the Walboros as tank feed pumps and then use a single large one. plus the use of multiple pumps can be utilized to feed the tank if required and since the walboros are much cheaper then multiple Aeromotive pumps its win win. plus i don't have to sump the stock tank (although that could still be done with my set up if i decided to switch to external feed pumps)

i decided to make the whole system "portable" for ease of install, fuel line routing, possible trouble shooting or temporary removal if i don't need the setup say for going NA while i rebuild something.

so the surge tank, A1000 pump, pre / post filters are all mounted on an aluminum plate.

now the big question is where in the car this goes >?< most regulation require a bulkhead between the passenger compartment and any fuel cell / pumps
well most sedans have this already so no worries for them but it poses a challenge for us.

i thought of making an enclosure out of the back passenger corner for this setup or using the spare tire well for this enclosure

i think once its finished more then i will be able to place it around and try different locations

Originally posted by eclipse982nrRST
Damn, Mark lays down some badass welds.

As I've been trying to tell you guys........