I wanna Turbo My wagon... What will i need?

[wagonist]

I would seriously suggest that you try to find a factory EFI tank & pump.

 

It would be one less pump to wire up & you wouldn't have to find a spot underneath your wagon to fit the surge tank.

[Skip]

I am sorry for sounding a bit daft

 

Would you be so kind as to explain what a "surge tank" is and why you feel it is such a necessary entity.

 

As far as I can tell none of my four turbo Subys have one.

 

The factory service manuals make no mention of them.

 

Fuel Tank -> fuel pump -> filter -> injector array ->FPR ->return to tank

[wagonist]

A carb fuel pump will self prime & can be run dry, ie with no fuel, without causing it to fail.

An EFI pump, due to the different mechanism, cannot do this & even one dry running can cause it to fail (mainly due to overheating). Beleive it or not, but EFI pumps use the fuel running through them to cool the bushes & stators in the electric motor to keep it running cool. Because there's no free oxygen, spark don't cause ignition of the fuel.

 

A surge tank is a tube around the fuel pickup point that stops the fuel from draining away from the pickup & running the pump dry while cornering, climbing, etc. The fuel return line is also aimed into this container.

 

Factory cars run a surge tank, or swirl pot as they're normally called here for the internal type, inside the fuel tank itself. Hence the reason there's no mention of it in your manual as Subaru doesn't want you to pull your tank apart, & you should have no reason to.

 

A swirl pot can be added into your tank by cutting it open, but I'd only be doing this on a car where there's no EFI option.

Another way of doing it is to use the carb pump to feed an external surge tank which is simply a tube with an inlet at the top (from the carb pump), an outlet at the bottom (to the EFI pump). It is also recommended to have the return line form the engine also feed into the top of this rather than going back to the normal tank.

Usually as these are fitted into the boot (trunk) of a sedan, an overflow from the near the top to this also drains down to the regular fuel tank.

 

As you can see, if there's the availability of a factory EFI tank, pump & lines, its a lot easier & neater to install.

 

If there's no option, I'd rather spend the money & fit an internal version, but otherwise you've got to find somewhere outside the passenger compartment to fit a 3 litre sealed container holding fuel with 4 hoses coming off it.

A very difficult task in a hatch or wagon.

[PoorManzImpreza]

umm so are EFI and carb fuel tanks a different part #?

 

that will REALLY suck as the EFI fuel tank on my parts car went with it to the great crusher in the sky...

[85Sub4WD]

An EFI pump, due to the different mechanism, cannot do this & even one dry running can cause it to fail (mainly due to overheating). Beleive it or not, but EFI pumps use the fuel running through them to cool the bushes & stators in the electric motor to keep it running cool.

sorry to disagree, but that is incorrect

my 1985 FSM SPECIFICALLY lists a proceedure for running the fuel pump on an EFI (turbo/NA) dry for tests (but a very short period of time) - which I have performed on the pump that has been in my car for 18k miles before installation as it was used - in addition to that I disassembled a subaru EFI pump in the JY that was badly rusted and found that there is an envalope that seperates ALL moving components from the fuel except for the propellor - it is also in the schematic diagram of the fuel pump in the FSM - there is an envalope to protect internal motor parts from gas, as gas is corrosive and could damage them (gas + copper = problem and gas + carbon brushes = problem)

 

early Bosch EFI systems (BMW/VW) had surge tanks - the Subaru does not need one/have one because of the afforementioned pump operating characteristics, and the fact that the return tube is located 2cm from the outlet tube on both FI and carb cars - different fuel tank part #'s are probably because of the difference in return line diameters - FI tanks also probably have a sock in them - Hitachi and Bosch are VERY different in their design of FI systems - I have worked on both

 

I have had my present setup - carb tank and steel lines (FI rubber) for over 18k MILES with no problems - many others on the board have also done the conversion in the same manner with no problems, and have put many more miles on their car than I have - it seems a waste of time/$ to swap components that will work perfectly fine as-is

[ausubaru92]

I was under the impression that the surge tank was needed (mounted at the front of the car) to reduce the chance of the fuel mixture leaning out due to the smaller carb fuel lines, just acts as a small reserve for WOT and steep corners ect.

 

All i need is conformation that i can run the old lines with just a efi pump in stock position and not have problems

 

thanks again guys

[wagonist]

I disassembled a subaru EFI pump in the JY that was badly rusted and found that there is an envalope that seperates ALL moving components from the fuel except for the propellor - it is also in the schematic diagram of the fuel pump in the FSM - there is an envalope to protect internal motor parts from gas, as gas is corrosive and could damage them (gas + copper = problem and gas + carbon brushes = problem)

 

Oops, mixed up the in tank pump of the later models with the external pump of the earlier versions.

 

my 1985 FSM SPECIFICALLY lists a proceedure for running the fuel pump on an EFI (turbo/NA) dry for tests (but a very short period of time)

How short is short? Bit ambiguous. Driving down a twisty road where the fuel is sloshing from side to side could deprive the pump of fuel to the point of stalling. This will definitely not do any good to the pump.

 

early Bosch EFI systems (BMW/VW) had surge tanks

Again, a bit ambiguous. How early are you talking. 70's? We're talking about the late 80's cars here.

 

85Sub4wd, You say you've opened up a fuel pump, how about a fuel tank? I have, when we cut at least one in half along the middle to weld a plate in to increase the capacity (the car had a 2" lift kit, so you can add 2" to the height of the tank, about 17litres)

There's a lot of probablies in your statement. I can confirm that Oz MPFI tanks have a larger feed & return line, & also have an open topped cylinder of metal around the pickup.

Just because the inlet & return lines are beside each at the edge of the tank, doesn't necessary mean that they end up at the same place IN the tank. in this case they do.

 

Please also remember where you are & where I am. I'm about 6 hours drive from AUSubaru92. & you are how far away.

What might work over there for your much colder climate may not work over here. Increase temp = decreased density by simple physics.

 

Were the US Subarus made in the US, or imported from Japan? All ours came from Japan.

 

My suggestion, use a surge tank or a factory EFI tank. They are not hard to get. (86/87 RX Turbo; 89,90 Leone Royale Sedan & Touring wagon; all Vortex's) Oz only ever got MPFI cars & they're getting old (not sold here since 1990) & rusty & wrecked. (I know of at least 2 Vortex's being wrecked at the moment within 5 minutes of my place) That's what I would do/have done/am doing.

[Ross]

 

What might work over there for your much colder climate may not work over here. Increase temp = decreased density by simple physics.

 

 

That is comlpetely negligable for what you are talking about (moving LIQUID fuel)

[ausubaru92]

i have made a decision, Surge tank (about 1ltr) mounted in the front wheelarch or something like that. i see it as the simplest way

 

 

But please any other suggeations welcome

[Skip]

These engines respond very well to an open exhaust and a cool air intake.

 

Here is a picture of one of my setups.

I have a cobra hood scoop feeding air thru the IC

 

Read around the picture,

if you have questions about any item please ask

 

[ausubaru92]

What is DAbomb tank and valve?

 

How did u control the timing from the dash?

 

And what is the enrichen valve?

 

thanks

[wagonist]

Inside the front guards is one place I wouldn't mount the surge tank.

Front right is full of air intake & washer bottle.

Front left (on our RHD cars) is the most likely to be hit in an accident & then you've got an open fuel supply near the battery just ready for ignition.

[ausubaru92]

Good point wagonist:drunk: we wouldnt want flaming sube

 

In the place of the spare tyre maybe?

[wagonist]

MUCH better idea.

[Skip]

au92:

Thanks for explain on the surge tank, never had a tank cut up. Have heard tell of swirl pots used on airframes I believe

 

wgnist:

Da Bomb is a storage tank and dash controlled solenoid valve,

it dispenses a mix of ATF and MMO into the intake manifold => huge cloud of smoke out the tail pipe

Used as an antitailgater tool

 

The ignition timing is controlled by a slipper clutch on the disty and a stiff cable

(like from a manual choke control)

The control knob is mounted under the dash.

It can move the distributor from lock to lock, used when the petrol octane and the engine are having disagreements.

 

The aux injector is a cold start injector from a Bosch CIS system.

It is triggered to add fuel at 8 psi and above.

I had a small bottle of LPG connected to it for a while.

Simply an antidetonaiton help.

I run this only at 12 to 14 psi but they need help at this pressure due to the

current ECU map and injector size.

 

Good on ya mate, hope this helps

[subaru_styles]

Da Bomb is a storage tank and dash controlled solenoid valve,

it dispenses a mix of ATF and MMO into the intake manifold => huge cloud of smoke out the tail pipe

Used as an antitailgater tool

 

 

AHAHAHAHAHAHA, that is awesome