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 Post subject: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Mon Jun 05, 2017 10:16 pm 
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Vehicle: MY12 XT Premium Auto White

Posts: 385
Location: Brisbane
They say the biggest problem in increasing horsepower on the factory Subaru Boxer engine is the fuel delivery. The factory system runs the fuel in series which tends to cause certain cylinders to obtain less fuel. In higher boost applications, these cylinders can lean out dangerously causing the motor to fail.

There are so many Google threads out there on this subject and it gets very confusing which are creditable or worthy.

Has anyone here in Aussie done their own Equal length fuel lines running to each fuel rail, using either the standard fuel rails,regulator or aftermarket rails, plus aftermarket regulator? And links to suppliers.

Especially keen to hear about DIY for the SH XTP Forester or a good aftermarket set up that doesn't cost the earth!

Cheers Al


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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Mon Jun 05, 2017 11:08 pm 
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I Say: Car mods are like OddBodz, you got to collect them all! -------------------------------------
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Ive done it, as have probably many many people. I wouldnt say its the biggest hurdle in getting more power out of a subaru (ej25). There are plenty of bigger hurdles such as fragile pistons and weak block layout. (Which will be a problem before the need to do much more than upgrade injectors and pump first.)

Its not particularily hard. Buy and fit the components, assemble the hose and hook up the plumbing. Done. You will need rails and a reg in order to go equal length parallel properly (because the OEM reg is built into one rail, so is awkward to circumvent). And you will want injectors aswell, as theres not much point upgrading the plumbing otherwise. Having an external surge can is definately an advantage, not just for anti-surge benifits. But also because an external can will allow for big or multiple pumps. (Which you will need at a certain power level anyways, again, probably before the need to do much more than pump and injectors.)

You dont need to use AN plumbing. It is kinda expensive. But it is used on alot of fuel rails and regulators and such. It does bolt together and is pretty secure in that reguard. If you do use it, make sure its the teflon tube variety, not the rubber hose variety. And make sure its a name brand like Speedflow, aeroflow, earls etc bought from a reputable supplier. Plenty of less than perfect hose and fittings out there that might be ok for some uses, but not fuel. Also, plan out your system so you only need to do one parts order. -6 or 3/8 will be fine for most users. Although if you want to support real high power then you could look at -8 feed. Along with multiple pump setup.

I use -6 Speedflow Teflon hose system. Radium fuel rails. Radium surge can with built in regulator. Earls or holley High volume fuel filter (cant recal exactly which). I have my setup go as follows :

Intank DW300 lift pump. At the hardline near the passenger side firewall i cut off the flared bead and fitted a hardline to AN olive crush fitting. From there it goes to the surge can with 450lph Walbro submerged pump. From there its -6 to the filter. (Filter is -8 with reduced down to -6) From there to the rails via a 'T' piece. ( 'Y' piece would probs be marginally better.) The rails are dead end, with no return. This is because the surge can has a built in dead end fuel pressure regulator. This reduces the plumbing requirements by nearly 50% (equals a few hundred bucks less worth of fittings if using a premium name brand teflon AN hose system). From the surge can it returns to tank via the normal hardline.

Having the surge can upfront has multiple benefits. Anti-surge. Can fit a large pump easily. Close to battery for short heavy guage cable run to pump. Easy intergration to fuel lines near passenger side firewalk/strut tower. If you are actually replacing the hose because your exceeding the flow capacity of stock, then having the can upfront means you wont need to replace the hardlines from tank to engine, as the surge can and main pumps are forwards of that. Although you would need to be making some serious power before needing to put larger hardlines in.

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Tue Jun 06, 2017 9:28 pm 
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Vehicle: MY12 XT Premium Auto White

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Location: Brisbane
Bram Bram, thanks for your input. 'Its not particularly hard. Buy and fit the components'.

The devil is in the detail.

At present I do not know of any 'Equal length fuel lines kit' that directly fits 2009 to 2012 SH XT Foresters.

Let me clarify my proposition here. I am tight as a fishers ass.

I need advice like this KISS! Keep It Simple Stupid. I will buy used in good condition or EBay if it is legit and works.

Let's suppose I start with the fuel line incoming from the tank. There are three lines, one is fuel. I know it had 98 RON coming out of it.

Yep I need that! What else is there.... Return line? Vacuum lines?

Do I need these?

Then after that let's say there is nothing left of the Subaru OEM set up. No fuel lines that used to go to the fuel rails, and no fuel rails anymore.

Brams rails are dead end, with no return. I like this idea, less complex set up. But can I get fuel rails that suit and fit my 2009 to 2012 SH XT Foresters?

I need a Fuel regulator and gauge?. Where in the scheme of things does the Fuel regulator and a gauge fit.

Before incoming fuel or after? Vacuum lines?

So I need proper fuel rubber hoses and clamps. And brass Y joiner fittings.

I do not need bling CN stuff.

Fuel Injectors, I am keen on Injector Dynamics 1000cc.

Please do not confuse me with other than advice on and links/kits that suit and fit the 2009 to 2012 SH XT Foresters.

Cheers Al


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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Tue Jun 06, 2017 11:45 pm 
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I Say: Car mods are like OddBodz, you got to collect them all! -------------------------------------
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Forester4thetrees wrote:
Bram Bram, thanks for your input. 'Its not particularly hard. Buy and fit the components'.

The devil is in the detail.

Its not really that hard. The only way your gonna get your head around it properly is if you get stuck in and just do it.

What i meant by that was your gonna need some rails, your gonna need some hose, your gonna need some injectors etc. Doesnt matter how much of a MacGyver you are, most peoole cant just build that stuff in thier garage. So your gonna need to open your purse and buy the building blocks.
Quote:


At present I do not know of any 'Equal length fuel lines kit' that directly fits 2009 to 2012 SH XT Foresters.

Your probs not gonna find any 'kits' that do it. Its kind of a custom thing. And at the level of modification that actually require custom fuel supply system, its kinda expected that your not gonna have a 100% standard setup the same as every other mild forester to begin with. And that your clued up enough to work it out yourself or cashed up enough to pay someone else to.
Quote:


Let me clarify my proposition here. I am tight as a fishers ass.

I need advice like this KISS! Keep It Simple Stupid. I will buy used in good condition or EBay if it is legit and works.

Let's suppose I start with the fuel line incoming from the tank. There are three lines, one is fuel. I know it had 98 RON coming out of it.

Yep I need that! What else is there.... Return line? Vacuum lines?

There will be 3 runs of piping coming up from the rear of the vehicle. On subarus they run along the passenger side, inside the cabin, and pop out the firewall near the passenger strut tower. 1 is fuel supply, this comes from the fuel pump in the fuel tank. (Via the in-tank filter on post 05 models).

There will also be a pipe for the return to tank. This carries unused fuel back from the engine.

Lastly the other pipe is an emmissions purge line. It takes fuel vapours collected in the charcoal tank, and directs them into the engine air supply to be burned off in combustion. There will be a little solenoid valve and sometimes also a vacuum operated valve to control the flow of vapours. This is an emmissions thing only, and although you dont need except for legality reasons, it doesnt hurt to keep it functional.
Quote:


Do I need these?

Yes
Quote:

Then after that let's say there is nothing left of the Subaru OEM set up. No fuel lines that used to go to the fuel rails, and no fuel rails anymore.


Then you will need to plumb up something to replace it. At which time you may change the layout from series to parrallel. Or use AN hose system. Or add a surge can. Or any combination of the above. If you are removing the pressure regulator, then you will need one to replace it. There is no right and wrong way of doing it. Actually yes, you can do it wrong. But there are many right ways to do it.
Quote:


Brams rails are dead end, with no return. I like this idea, less complex set up. But can I get fuel rails that suit and fit my 2009 to 2012 SH XT Foresters?


Most, (but not all) aftermarket fuel rails for Subaru will support this feature. Typically, most aftermarket rails will be a pretty big chunky, machined billet ally block. Because this is strong and sturdy, and looks porn. They commonaly have an O-ring Boss female threaded connection or sometimes a NPT female threaded connection at each end. (I think the ORB is more common because NPT isnt that good at stopping leaks, and the threads get mangled up from use. That is actually how they are designed to seal.)

They usually do this because its easy to change the adapter to suit the end users particular system. For example some people might want to use standard EFI hose, so they simply screw in a hose barb. Some people might want to use -6 AN hose, so they simply screw in that connector, and some people might want to use -8 AN hose, so they screw in that connector, and some people like me might want a dead end system, so they simply screw in a plug at one end. Most decent brand fuel rails will come with adapters to suit the common plumbing options included.

Quote:


I need a Fuel regulator and gauge?. Where in the scheme of things does the Fuel regulator and a gauge fit.

Before incoming fuel or after? Vacuum lines?

You need a fuel pressure regulator if you remove the original. You dont need a guage all the time, but you will need a way of measuring pressure when setting the system up. Most people with aftermarket regs put little guages in and just leave them there full time. But technically its not needed, aslong as its measured and set properly during initial setup.

99% of the time, the fuel regulator goes after the fuel rails. This is standard return to tank EFI. Its job is to keep a certain pressure trapped before it. (In the fuel rails). It keeps this pressure before it by only metering out a certain amount of fuel that it releases back to tank down the return line. If the pressure gets too high, it opens up and releases more fuel. If the pressure gets too low, it closes up and traps more fuel. And maintains its pressure by releasing just enough of the unused fuel to tank. The fuel reg also needs a manifold pressure refference so that it can adjust and maintain a certain pressure drop over the injectors, even as manifold pressure varies.

Then you get dead end fuel regs. If OEM, these typically are often down the back near the pump either in or ontop of the fuel tank. They still work like a conventional fuel reg kinda. Except in reverse. They aim to keep a certain pressure AFTER the fuel reg instead of BEFORE it. And there is no return from the engine/fuel rails. Instead they bypass and meter off the fuel back to tank at the reg, usually internally to the tank and maintain the the pressure in the lines after the reg that way. These typically dont have a manifold pressure refference. Instead just keeping a flat pressure. Although my one does as its aftermarket and kinda designed to replace what a standard fuel reg does.

Each method has its pros and cons. The return to tank method is very common, and is by far the industry norm. Most aftermarket fuel parts are designed around it. It always returns the fuel to tank and replaces it with fuel from the tank, so it doesnt sit in the rails getting hot.

The dead end system has less plumbing requirements and is simplified in layout. Less plumbing means less places to fail. And i like that. But its actually more difficult to setup, because less aftermarket companies do it that way. So less choice in how you do it.
Quote:


So I need proper fuel rubber hoses and clamps. And brass Y joiner fittings.

I do not need bling CN stuff.

This is easy and cheaper way of doing it and it works fine. Infact it works so good it is exactly how OEMS do (used to do) it. They just use regular EFI hose and barbs / hose clamps. Although probs not with brass Y fittings lol. Its easier for OEMs to stamp out metal hardlines, than it is to turn brass fittings.
Quote:


Fuel Injectors, I am keen on Injector Dynamics 1000cc.

Please do not confuse me with other than advice on and links/kits that suit and fit the 2009 to 2012 SH XT Foresters.

Cheers Al

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Wed Jun 07, 2017 12:58 am 
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Vehicle: MY10 XT

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My SH is sbout to go in for a forged bottom end rebuild and all the other mods for a e85 280kw atw setup. Was told that there is no need to touch the fuel lines even at that level. Only fuel changes is the DW300 and id1050 injectors.


Last edited by Tobyo on Tue Jun 13, 2017 11:26 am, edited 1 time in total.

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Wed Jun 07, 2017 7:08 am 
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Vehicle: MY05 XTL - Black

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Location: Tanah Merah - Brisbane
Forester4thetrees if you wish to look at my parallel rail setup feel free to come by and have a look. While I have an SG, the setup is basically the same.

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Wed Jun 07, 2017 10:04 am 
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Vehicle: MY99 GT bare shell on stands

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Location: Kyneton, VIC
Equal length, parallel, all OEM hardlines thrown in the bin. Stock FPR, gates barricade E85-safe hose. A little shy of $100 in fittings and hose as far as I remember, but way cheaper than any full aftermarket kit.

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If I didn't have 2 cars worth of EFI hose clamps that setup would have been more expensive than it appears. Rails are old perrin units with 1/8 fittings. Originally I was going to use stock rails, but after swaging the cut ends to fit hoses I accidentally bent one and chucked it all.

Tobyo wrote:
My SH is sbout to go in for a forged bottom end rebuild and all the other mods for a e85 280kw atw setup. Was told that there is no need to touch the fuel lines even at that level. Only fuel changes is the DW300 and id1050 injectors.


That's concerning, that you would be advised of such. There are so many instances of dead EJs due to lean conditions in the rear-right cylinder -- close to turbo, underneath coolant top tank, last in series for fuel supply with uninsulated hard lines throughout engine bay. There was a tracked SF parted out just last month because that cylinder leaned out. It's just not worth the risk to go to all that effort and expense and leave the series fuel feed as per stock. The limitation isn't in the internal diameter of the stock fuel system, it's in the uneven pressure and temperature of the fuel supplied to the final cylinder prior to the regulator.

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Tue Jun 13, 2017 11:06 am 
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Bram wrote:

Intank DW300 lift pump. At the hardline near the passenger side firewall i cut off the flared bead and fitted a hardline to AN olive crush fitting.


Hey Bram,

how did you go about cutting the hardline near the strut tower? it seems getting a tube cutter in there would be impossible and using the likes of a dremel or other cutting disc seems dangerous and messy in regards to leaving metal in the lines that would potentially be fed back to the tank or in to the injectors.

Ive just done my whole engine bay in teflon braided hose and fittings but it annoys me that i have rubber going from my hard line to inline filter and also from my flex sensor back to the hard return line

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Tue Jun 13, 2017 11:15 am 
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dantheman88 wrote:
Bram wrote:

Intank DW300 lift pump. At the hardline near the passenger side firewall i cut off the flared bead and fitted a hardline to AN olive crush fitting.


Hey Bram,

how did you go about cutting the hardline near the strut tower? it seems getting a tube cutter in there would be impossible and using the likes of a dremel or other cutting disc seems dangerous and messy in regards to leaving metal in the lines that would potentially be fed back to the tank or in to the injectors.

Ive just done my whole engine bay in teflon braided hose and fittings but it annoys me that i have rubber going from my hard line to inline filter and also from my flex sensor back to the hard return line



I just used a dremel cut off wheel haha. Then flushed the lines back after. I was more worried about catching some residual fuel vapour on fire from the sparks.

The metal hardline can be gently manipulated to different angles etc aswell.

Once i cut off the flared bulge. I then think i may have had to leel back a thin plastic sheeth off the hardline. Then a quick clean up with fine sand paper. The i used the AN to hadline fittings. They clamp down on the hardline with a brass olive conpression fitting.

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 Post subject: Re: Anyone done Equal length fuel line runs to each fuel rail
PostPosted: Tue Jun 13, 2017 12:01 pm 
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yeh thats exactly what i was worried about too.

my return line on my sf has a bend that aims it towards the front of the car but id ideally like to be able to bend it towards the firewall or cut it off and put a 90 degree fitting on it.

Its purely for looks after doing everything else in braided and then having the rubber hose right at the end which bothers me every time i look at it now haha

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