I running a turbo G13b and I am wondering how the fuel system should be best set up.

The fuel pump im running has a 12mm inlet and an 8mm outlet, so I need to modify the left hand tank outlet to 12mm and the return line will be placed at the top of that tank. Just running the standard mini fuel line as the return.

Now here is my problem. I have twin tanks and Im not sure how to best set them up. I have two options.

1. Modify the outlet of the right hand tank to 12mm and add a T section into the outlet of the left hand tank fuel line and add the right hand tank feed into that. So basically the same as cooper S just a bigger size fuel line.

2. Modify the right hand tank outlet to 12mm once again, but modify the right hand tank with another outlet of 12mm also and connect the right hand tank into the left one. So basically the right feeds into the left and hopefully the 12mm line will help to keep them similar heights due to the fuel all coming and returning to the left.

So which one sounds like the best option? or do people have other ideas that they have used? i don't really need a surge tank as I have a decent size fuel filter before the fuel pump which will also sort of work as a surge tank, not that you should really need one being gravity fed, the pump can take as much fuel as it wants when it wants.

Anyway hit me up with your thoughts.

Cheers
Todd

low pressure pump for each tank feeding surge tank. use surge tank to feed high pressure. could use fuel soliniods from gas setup ups and wire it so you could alternate between tanks if ya wanted. just a thought

Can't say I have actually thought about that option and it sounds pretty good. But I was going for the simplest option that will also work rather well. Doesn't have to be anything too fancy and I need to save space in the boot for an amp and sub as well

Will have a think about it though, cheers.

run both lines into a small tank unter the boot floor in the subframe cavity. this will give you a gravity feed and no pump hassles.

Remove the fuel pressure regulator from the end of the fuel rail and plug off the end. (you could not plug it and run a loop back to the start of the fuel rail as well)

Fit the fuel pump next to the small grav fed tank and have the infeed to the pump inserted into the bottom of the tank.

Fit a T piece to the outlet from the fuel pump.
One end of the tee piece run upto the fuel rail.
One end of the tee piece attach the (now removed) fuel pressure regulator
Run the outlet from the fuel pressure regulator into the top of the small tank.

What you get is a non modified mini fuel tanks, a single fuel line running forward and a neat little pump and tank setup that doesnt have lift pumps, wires and pipes running everywhere.

Simple is best

I dont want to hear crap about over heated fuel or pressure line losses or other crap as it doesnt happen in reality.

The smaller the "pump tank" is the less time recirculated fuel is in there, any line losses are solved by squeezing the pressure regulator with a socket in a vice (if needed)

So how big of a tank do you use under the floor? It sounds like a good idea, just can't picture it all fitting in down there as there isn't much space.

Do you have any pictures of the setup on your own car? Would be good to see how you did it. Sounds like a top idea.

yes you can fit a tank under the back...
250 X 400 X 100 about 10L
100 being the roughly the same as the battery box height.
perhaps too big for a grav fed surge tank.

You will also have to run a small pipe from the intake plenum back to the pressure regulator. This required to maintain a constant differential pressure .

Unfortunatly thats the true and the pipe works a a resevoir so the fuel delivery does vary with quick throttle/engine changes.

I got no idea what any of this talk about plenum and pressure regulators is about. I haven't got that far yet, I just want to set up the fuel stuff in the boot (or under it) so I can finish off the boot and move on. If this pipe doesn't go to the boot, then I can worry about it later on.

the suggestion (the whole remove reg thing) is that .. a suggestion. I think that it is the hard way to do things, but you have many options.

Don't put the filter before the pump. pumps don't like to draw against a load.. the filter will restrict your pump and it will shorten its life. They are much happier to push the fuel through the pump. Make sure youuse a EFI filter too.
You could run a return line, keep the stock pressure reg and thats it. Because the twin tanks will balance out the fuel (assuming you have an pipe to connect the two at lowest section of the tank, then you can tap into either tank, or into the balance pipe for the inlet to your pump. The return can go back to either tank, or straight to your little tank under the boot.
I have (well its still to have fittings welded to it) a little tank (250 x 350 x 100) which will be mounted under the boot floor, I havn't figured out where (center or to the passenger side) as it all depends on the position of the exhaust. It will have three lines... fuel in (gravity fed 1/2) fuel out (3/8 or 10mm to pump) and return (5/16 or 8mm). the tank is made from 4mm ally...its what I had at home.
I will post pics later this week when it is welded together.

What i have is a std & cooper s tank joined with the original 6mm balance line , An electric SU pump fills the surge tank with a filter just after the su pump , ---- Off the surge tank there is the return line which feeds back into the std mini tank which i fitted with 2 seperate brass fittings in the top of the tank , Off the outlet of the surge tank is a Bosch Motorsport 580 EFI Pump with 15mm inlet to the pump and 8mm outlet (EFI Hose) which supplys the fuel rail with an EFI filter just after the bosch pump , The return from the fuel rail is 6mm line (EFI Hose) which returns to the surge tank . The other fitting on top of the mini tank is used for a vapour line from the carbon canister




Sounds complicated but is fairly simple when you get ur head around it , But i dont have to worry about space in the boot for stereo gear as the car dosent have a radio

hmm does the tank have to be as big as suggested or would it be quite ok to make a smaller one?

I have a VL Turbo Fuel pump (as far as I know) and a filter that goes with that pump, so there for it should be an EFI filter yes? Whats the difference?

So there isn't any problem running the fuel return line into the little tank even though the little tank will always be full?

Wouldn't it be a good idea to have the fuel filter before the pump to stop any crap going through the pump? or could you have another one on the feed line into the little tank?

hmm this is all new to me so bear with me. This is what I could plan to do, so let me know if it sounds about right.

Run a 1/2 inch line (think thats the standard size) from the RHS tank to the LHS tank where it joins into a T-piece (just like the copper S as far as I know), this goes through the floor (maybe through a filter) then into the top of a tank (size yet to be determind), from this tank there is 3/8 line out the bottom into the fuel pump and then that goes off on its way. The return line is the stand mini fuel line which will return into the top of the little tank. That about how it should be?

Is there any problems with gravity feeding into the pump? The fuel will have enough downforce from the tanks to feed the pump enough fuel to get it started?

Cheers
Todd

Good to see people who like answering stupid questions

I would run the return back into the main tank, and forget about a filter before the pump. Apart from that, it all sounds good.

I am using a Subaru pump with a VL filter (because they are big & they're cheap). Just make sure everythin is clean before filling up the system for the first time, and then let the pump run for a while. That way it will filter all the fuel before you you start pushing anything through the injectors

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Too many cars, and too little time.

Cheers...have to get to it and rig it all up then. Then I can move onto other things