fuel tank outlets for both turbo and N/A
Turbo Mini Forums

hi guys , im measuring up to have an ally fuel tank made to fit in the spare wheel well in the boot , im thinking about what outlets i need on it , im thinking a 6mm outlet should be enough for more or less any spec NA a-series engine shouldnt it ? and what will i need for turbo applications just a 6mm return ? obviously plus a breather nd a boss for a gauge sender ? is this all or is there something ive missed ? dont wanna get it made then find out i needed another outlet !

thanks

Ant

I have 8mm feed and return, inside diameter.
But some use even a bigger return of 10mm.

there is nothing wrong with a A-series that a turbo can't fix.

www.turbomini.nl

6mm return on a turbo will be too small, i use (as above) 8mm ID.

both 10mm for me

Yes i moved to the darkside

Instagram @jdm_brett

Outlet from tank to pump, IMO should be a minium of 12mm, and have suitable surge protection/baffling to prevent the pickup seeing air.
Most efi pumps use at least a 12mm inlet anyway.

Return of 8mm OD ( solid pipe ) would be ideal for any application.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

i thought the return should be the same size if not bigger than the feed?

Edited by MarkGTT on 30th Jul, 2010.

Feed to the pump is not the same as feed to the FPR/engine.

And often, you can get away with a smaller feed than return. But in the case of a system using an efi pump with a carburettor, it would make sense to have at least the same size feed and return.

Which will have nothing to do with the tank outlet size.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

so hows about an outlet of 8mm and a 10mm return ? wont be going turbo for a while yet anyway :)

I've fitted a 12mm outlet to my tank. As Steve says above, the pumps are usually have this size fitting.

Otherwise, you will need to use reducers.

Saying that, I used to have a 6mm outlet with reducers to the pump for years without a problem.

In the 13's at last!.. Just

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

The point of the return is so that you can get the excess fuel away from the pressure regulator, if it's too narrow it won't be able to regulate the pressure low enough. In theory a fatter supply line will feed more fuel to the regulator so you will potentially over power it and get too much fuel at the carb.

On our metro van we have the standard factory feed (around 5 or 6mm) and a 10mm o.d. return. That works a treat.

i think stevieturbo is pointing out the input on THE PUMP is (iirc 13mm) and the feed to the pump from the tank should be of similar size
the OUTPUT from the pump is 6mm (maybe 8mm)
the piping from the pump to the fuel pressure regulator is usually the 'fuel pipe diameter' most refur to when stating size

so for the fuel tank inlet/outlet diameter, id listen to steve (even though mine is different )
for fuel pipe, id (personaly) use 8mm feed and 10mm return
(or 10/10) im my case

Yes i moved to the darkside

Instagram @jdm_brett

Metro turbo pump has an 8mm outlet.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

ok sorted thanks guys :)

Listen to steve.

You do not need a 10mm return, 8mm is more than adequate, infact a 6mm would do the job (and I have proof of this too).

The issue is that a Metro pump (in fact lots of pumps) have 12 or 13mm inlets and 8mm oulets. And from experience, it's a pain to mate a 12mm inlet to a 6 or 8mm outlet with one pipe.

It's a common thread on thsi forum that believes the return should be massive. It needs to be no bigger than the FPR hoise size; so 8mm feed and 8mm return is spot on. As said though I ran 8mm feed and 6mm rtn with no issues.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

ok cool thanks mate :)