19 replies to this topic

[sherly]

Hi,

I'm in the process of sourcing a fuel tank for a turbo mini and I'd like to know the differences between SPI and MPI tanks.

From searching the forum, MPI tanks seem to be the favourite choice, but I'm assuming it's possible to use an SPI tank?

Also what sort of price do these tend to go for and how available are they?

Cheers,
Mart

[Turbo Nick]

as far as i'm aware the mpi tank puts out a higher pressure than the spi. i'd say the mpi is the one to go for if you intend on running highish boost but cant say for definate as i dont know anyone who's actually tested the pressures. basically you need a pump that will run at least 7psi above boost pressure, only needs to be 4psi but say 7psi to be safe.

price wise anything from £40 upwards really...

[sherly]

Nice one - pressure capability was the only difference I could think of.

I'm not thinking of going too lary with the boost but it might be worth safeguarding for the future and go for the MPi tank.

Which mini's were MPi? Are these tanks fairly easy to get hold of?

[Turbo Phil]

96 onwards i believe were all MPI.

Phil.

[Dog]

Which tank would you recomend for a boost of up to 15psi?

[Turbo Phil]

From what i've found out either SPI or MPI tanks should be fine. There are people using both without any problems, so take your pick.

Phil.

[rsroadkilla]

or you could always modify your existing tank...

Simple enough to do, plus your save yaself £50-60!!

[Jammy]

But if you do that, you have to pay for a fuel pump, maybe a pressure regulator, and I'm not sure I'd want to take a change with a fuel tank that may leak??

[Sam]

You'll still need a fuel pressure reg..

[sherly]

or you could always modify your existing tank...

Simple enough to do, plus your save yaself £50-60!!

I had thought about doing this - but it just seemed easier and neater to use an injection tank.

Whats the best/neatest method of plumbing in a fuel return line to the tank? I'm assuming you can buy some sort of spigot which secures with a nut and a seal......

........as I don't fancy welding the tank.

[Turbo Nick]

i'm not running a return into my tank. the return feed from my regulator is fed back down and round and T pieced into the fuel feed between the tank and the pump. There are quite a lot of people doing it this way now and as far as i know no-one else has had any ill effects from it.

[Bigbudders]

I think 96 were still Spi's

97 onwards Mpi

[Sam]

i'm not running a return into my tank. the return feed from my regulator is fed back down and round and T pieced into the fuel feed between the tank and the pump. There are quite a lot of people doing it this way now and as far as i know no-one else has had any ill effects from it.

Thats what I will be doing..

Simpler then welding in a return.

[Sprocket]

i'm not running a return into my tank. the return feed from my regulator is fed back down and round and T pieced into the fuel feed between the tank and the pump. There are quite a lot of people doing it this way now and as far as i know no-one else has had any ill effects from it.

To point out for safetys sake, that plumbing the return back to the pump feed line is only satisfactory on a standard tank with an external pump. Do not try this with the injection tank as the pump is in the tank itself. Plumbing the return in like this on The injection tank will over pressurise the carb sqirting fuel everywhere. Not that it will happen, but there are some people that just dont know what they are doing and need telling, And not that you are like that, but it needs to be said

Just to clear that up before some one tries it

[sherly]

Just for the record the options I think I have are

1. Modified (with return line) non-injection petrol tank with external fuel pump.

2. Standard SPI tank (which has pump in tank).

3. Standard MPI tank (which has pump in tank).

Of all of these the injection tank seems the neatest solution - no external pump to mount/plumb in and no return line fitting to add to the tank.

IMO its seems a bit gash to t-piece back into the fuel supply line near the tank - I'm sure I 've read somewhere that the return should be as high in the tank as possible?

Not sure on the reasons for this though.