ALFAGTV6.COM

[PietereQ]

Since I experienced the charm of fuel starvation on hard right turns on track in my gtv6, that seems to be the correct solution. BUT I have a question to you guys out there; most stuff I found on net mainly refer to surge tanks installed on a cars converted from carbs to EFI. Like here:

My question is, in a gtv6 can leave the original fuel pump, or the first pump has to be the low pressure one? My idea was to run the identical two stock pumps - reasonable or not?
thanks
pete

[Giuliettaevo2]

i think you can use two original high pressure pumps. the return line from the surgetank to the original tank will prevent it from becoming pressurized.

You could also have your ogiginal tank cut open and have some baffle plates installed. this way your fuel won't move to far away from the pick up point in a corner. installing another pick up point on the other side of the tank is also an option, just install a T-piece between the two pick ups and run the pump of that.

[MD]

Peter,

My prefered solution is this:-

A lift pump installed inside the fuel tank. This fills a surge tank. The surge tank supplies the high pressure pump to the fuel rail. The fuel rail return goes back to the surge tank as in the illustration you have provided.

Generally speaking, pumps have a greater ability to push than to draw. Having an immersed pump minimises any head pressure to be overcome to lift the fuel to the next stage.

There are of course other pros and cons either way but this is just my preference
Cheers, MD

[Giuliettaevo2]

if you make the surgetank aprox. 2 litres you'll have a minute supplie of fuel. would be hard to loose all supply to the pickup point in the original tank for a whole minute.

in-tank pump is also a good one to feed the surge tank. i don't exactly remember how the GTV6 tank looks like but i thought there was no pump inside so there wouldn't be an easy way to put a pump in there without welding a entrance hole. would be a better option since airsucking will kill any pump eventually and the in-tank pump could be placed/protected better against this.

[Mats]

Some thoughts. You want to install this because you have problems with the original install, yes?
Why then keep the troublesome original install and add another pump? Would it not be better to install a pump that does not need to be primed as a feeder to the surge tank and the original pump as a HP pump to the rail?

The HP pump does not like to be run w/o fuel so it will go bad if you drive it without cooling/fuel intermittently, it also moves way too much fuel if you run it without any pressure diff, that translates to heated fuel and more current draw from the alternator.

[PietereQ]

Thanks guys, really interesting concepts you have here. I really liked the submersible pump idea but thats to much work. Mats from what you wrote I assume that you would go for the low and high pressure pump?
Ok I was trying to come up with something and, erm. please dont flame me here, im running a fever right now (thanks to our "warm" spring), if you see some irrational ideas here:
yea I know fuel return line enters the tank from bottom...

[Mats]

Looks like a complicated way to make the fuel system perform weird.
Go with the first plan or make som bulkheads in the tank to control the fuel movements.

[Giuliettaevo2]

this will work...

just put the return line also on the aux. tank. and use more then one pickup-point on the original tank, preferably on both sides of the tank. larger diameter hose really helps here.

Used that setup on the Opel Kadett C Caravan with a 2.0 16v turbo engine from a friend, worked great.
http://www.youtube.com/watch?v=f2LBVPmkuZY

[ar4me]

just install a T-piece between the two pick ups and run the pump of that.

When I did the fuel cell and fuel line plumbing in my race car all information was pretty clear that a simple T from two pick-ups to a single pump would not work. Each pick needed its own pump. I had starvation during cornering with single pick-up + single pump, but solved it with dual pick with individual pumps. Outputs of pumps after check valves are T'ed together. That worked for me.
Jes

[PietereQ]

Guys I'm ashamed, I know it's been "a while" since this thread started, but...
Well one question, can I place EFI pump vertically? Or they need to be mounted horizontally?
thanks

[GTV27]

Maybe I'm over simplifying the problem (and therefore the solution), but wouldn't a small tank between the main tank and the pump that sits below the main tank (not a problem in a GTV6 as the main tank is so high), holds a couple of litres and is vented back into the main tank (so any air drawn in can escape), ensure a reasonably consistent supply (unless you wanted to do skidpan work with only a few litres in the tank ) Maybe that is what you meant with the diagram?

My own low bucks racing solution is to run with at least 20 litres on board

Oh, so long as the pump is below the tank, I don't see why its orientation would be an issue?

[MD]

Well I have never pulled one apart but my guess is this. In the vertical mode, it is morelikely to maintain prime which for a pump is very important but if you run a lift pump in conjunction with it, then it probably doesn't make that much difference.

[PietereQ]

Well, it's the priming/friction/bearings whatever i was concerned about. Since I'll place it below the surge tank hope there will be no problems. Well no risk no fun.
Pics of a mock setup:

[ar4me]

Are you mounting surge tank and fuel pump in the engine compartment?

I think you may get hard starting since surge tank and fuel pump sits above main tank, and hence fuel may drain back to main tank when engien is turned off - not sure it will run well even if you get it started. The pump would have to suck air/gas all the way from the main tank through the surge tank - I doubt that will work. These pumps are not good at sucking. Usually, it is all mounted at a level below the main tank so that gravity will feed the pump. Maybe you have a separate feed pump?

Anyway, I guess you can always try and see what happens.

Jes

[Giuliettaevo2]

You will also be heating up the fuel which isn't very good.