Fuel line routing work check

[818speed]

I’m wrapping up my work on the fuel system and would love some input on what I’ve done so far. I have a Boyd tank with a rollover valve, an EJ257 motor, and retained the stock fuel rails and PCV spaghetti because I want to keep a charcoal canister. All lines are routed through my rear firewall.

The fuel delivery line is attached to a small in-line filter, then to the fuel damper, and finally FFR quick connect to the top fuel rail.

The fuel return line uses the quick connect to the middle fuel rail, then the return damper is spliced in, and routed back to the Boyd tank.

The fuel evap line seems to be the biggest challenge and I can’t to find any definitive answers, but I wanted to incorporate the Mazda canister discussed in other threads to keep the size and complexity down. I clamped a fuel line to the Boyd tank roll over valve and the other end to the canister. I clamped a smaller diameter coolant hose (didn’t have a fuel hose the right diameter) to the bottom fuel rail, then reduced it further with a vacuum line to connect it to the canister. Finally, I ran the drip line down to below the chassis.

Am I on the right track?

[STiPWRD]

The fuel evap line seems to be the biggest challenge and I can’t to find any definitive answers, but I wanted to incorporate the Mazda canister discussed in other threads to keep the size and complexity down. I clamped a fuel line to the Boyd tank roll over valve and the other end to the canister. I clamped a smaller diameter coolant hose (didn’t have a fuel hose the right diameter) to the bottom fuel rail, then reduced it further with a vacuum line to connect it to the canister. Finally, I ran the drip line down to below the chassis.

Am I on the right track?

Could you clarify the last bit about connecting a coolant hose to the fuel rail? A picture would help. Generally, if you have liquid fuel or even fuel vapor, it will eventually degrade non-fuel rated rubber.

I'm also running the Boyd tank. I ran the vent fitting on it directly to a yamaha scooter charcoal canister. Seems to work fine. I capped off the unused evap ports on the intake manifold.

[818speed]

I attached the coolant line to the bottom fuel rail as a temporary solution, ultimately I plan to change it out with an appropriately sized fuel line. Would I be able to cap the evap rail if I retained the PCV? I saw that people who deleted the evap system capped it at the manifold, but I’m not sure I’d want to remove it at this point.

[818speed]

Tankfuellines.jpgFirewall canister.jpg

[Shawn818c]

I'm about to embark on a similar endeavor so this is ideal timing for me...

On the lower rail that isn't the PCV system, that is for the Evap purge. Might be some confusion there. The 2 valves, one at the turbo inlet and one at the intake manifold, I think are both normally closed. So STi is saying you can cap the metal line below the quick disconnect fittings.

Where is the inline filter?

Are you deleting all the EVAP codes from the ECU?

Do you have any vents planned on the fill neck?

You need to cap or remove the brake booster vacuum line. 1/8" NPT?

Do you have plans for an aftermarket fuel pressure regulator?

Also, how old is that Boyd tank? Seems like an early version...

[818speed]

I found 1/4 and 1/8 fuel lines, as well as a brass barb to splice them together. This will allow me to connect the bottom fuel rail to the charcoal canister, without fearing the lines will degrade over time.

I’m talking about the evap system, the Subaru diagram indicates that a component originally connected to the canister is called a purge control solenoid valve. I think I was confused on the direction of the flow. Looking at the diagram that I attached, the flow appears to go from the canister to the manifold, so it seems that leaving this will allow the purge valve to pull vapors from the canister, as intended.

EVAPORATIV.jpegImage.png

The inline filter is going to be mounted with rivnuts along the driver-side top rear chassis brace, after the fuel line exists the rear firewall and before the damper. It's just hanging in my previous photo.

There are likely going to be a number of codes thrown when I first start this beast up, secondary air system is gone, no seatbelts, no air bags, etc. However, I plan to code them out with an AP or take the car to a tuner to dial everything in.

According to everything I've read, it would seem wise to add a vent in the filler neck. I plan to tie the filler neck vent line into the fuel line from the rollover valve, then connect the line to the charcoal canister, but I haven't come across anything off the shelf that I can use to make a filler neck vent yet.

I know the brake booster port is still open, it took me forever to figure out what to do with it, but I found that I can just use a 1/8-28 BSPT plug. The part itself isn't expensive at all, but everywhere that seems to carry it charges 5x the amount for shipping and carries nothing else I need, so I haven't pulled the trigger yet lol. However, I think this Triumph part should work just fine: http://www.adeptpowersports.com/oem-...RoCowcQAvD_BwE

Is there a specific reason I should consider an aftermarket fuel pressure regulator?

My Boyd tank is a bit older, I believe 2014-15. Is there a reason I should be concerned?

[Shawn818c]

I'd rather keep a closed fuel system too. However, there is one more solenoid on the canister. I think that opens, to allow in, when the system is purging to the inlet / intake.

Just wondering why a second filter is required since there is one in the tank, i hadn't planned for an in-line filter.

I know mechie3 made a custom piece and the factory has a vent in the fuel neck. I want to be able to fill the tank like it is OEM.

From what I've read the stock fuel pressure regulator isn't sufficient for aftermarket pumps hence the need for an aftermarket regulator.

No worries on the Boyd tank. I see the fill neck has changed and I've read the internal baffles had a revision to reduce starvation, either way a vast improvement over the FFR units.

[818speed]

My understanding is that the solenoid in the canister is used during an ECU self check. I would imagine it opens and closes a valve inside the WRX canister, but as long as the vapors make it into canister, then it will at least reduce the smell of fuel.

The inline filter may be redundant. However it was inexpensive and will ensure nothing but gasoline makes it to the engine.

Thanks for point out the fuel neck vent from Mechie. I’m definitely trying to do whatever I can to make filling up as painless as possible.

I’ll look into the fuel pressure regulator. I’m hoping that leaving both the feed and return dampers will prevent any issues with fuel pressure.

I plan on using the 818 primarily on the street, so I’m not too worried about starvation. I suppose if it’s an issue I can install a HydraMat or something.

[STiPWRD]

There are likely going to be a number of codes thrown when I first start this beast up, secondary air system is gone, no seatbelts, no air bags, etc. However, I plan to code them out with an AP or take the car to a tuner to dial everything in.

Just curious - if you're planning to disable the codes from the evap system, why go through the trouble of installing the evap components such as the purge control solenoid? IMO unless you're trying to preserve the OEM emissions system or you have no way of clearing the codes, there's really no reason to keep these components. Once the fuel vapors go through the charcoal canister, they can be vented directly to atmosphere. The canister pretty much eliminates any kind of fuel smell.

By the way, the ECU will not trigger any codes if you don't have airbags or no seat belts (same goes for ABS). You'll just get an airbag or seat belt warning light on the gauge cluster, but no CEL. These warning lights can be fixed usually but grounding the right wire. The secondary air system could, however, trigger a code.

I know the brake booster port is still open, it took me forever to figure out what to do with it, but I found that I can just use a 1/8-28 BSPT plug. The part itself isn't expensive at all, but everywhere that seems to carry it charges 5x the amount for shipping and carries nothing else I need, so I haven't pulled the trigger yet lol.

You can also simply cap the barb for the brake booster. I used a black silicone cap, I believe it was 10mm but they sell all sorts of sizes.
https://www.ebay.com/itm/10PC-8mm-10...UAAOSw5R5dVMsn

[STiPWRD]

Just wondering why a second filter is required since there is one in the tank, i hadn't planned for an in-line filter.

From what I've read the stock fuel pressure regulator isn't sufficient for aftermarket pumps hence the need for an aftermarket regulator.

I'm also running the in-line OEM filter. Not certain but I believe the in-tank filter on the pump filters larger particles and the in-line one filters finer particles. It's good insurance to keep the injectors from getting clogged and came that way from Subaru.

Regarding the stock fuel pressure regulator - I agree, they are generally not as stable as some aftermarket regulators and may have fluctuations in fuel pressure. You may be ok with the stock FPR but it's something that can be upgraded later if you have fueling issues. I ended up getting an Aeromotive FPR and aftermarket fuel controller since the Stealth 340 pump in the Boyd tank draws almost double the current of the OEM pump. Some people hard wire a beefier wire to the pump directly (bypassing the fuel controller), this is where the stock FPR will definitely not be able to keep up. I tried this out and ran very rich.

[818speed]

Just curious - if you're planning to disable the codes from the evap system, why go through the trouble of installing the evap components such as the purge control solenoid? IMO unless you're trying to preserve the OEM emissions system or you have no way of clearing the codes, there's really no reason to keep these components. Once the fuel vapors go through the charcoal canister, they can be vented directly to atmosphere. The canister pretty much eliminates any kind of fuel smell.

I suppose I don’t have a legit reason.. I figured the evap system only weighs a few pounds and didn’t want to upset the operation of the fuel system too much. This vapor canister stuff was giving me nightmares.

By the way, the ECU will not trigger any codes if you don't have airbags or no seat belts (same goes for ABS). You'll just get an airbag or seat belt warning light on the gauge cluster, but no CEL. These warning lights can be fixed usually but grounding the right wire. The secondary air system could, however, trigger a code.

Thanks for pointing that out, I thought I could code out the dummy lights, but grounding them is easy enough. I just anticipate that I will need to tune the car anyway since the short block and most of the internals are all new. I read somewhere that removing the secondary air system generates a few CEL codes. I also installed a kit from iWire that replaces the driver's side pump with an adapter to utilize a stock MAP sensor in place of the non existent Barometric pressure sensor, so that will need to be coded in.

You can also simply cap the barb for the brake booster. I used a black silicone cap, I believe it was 10mm but they sell all sorts of sizes.
https://www.ebay.com/itm/10PC-8mm-10...UAAOSw5R5dVMsn

Excellent! I’ll just cap the brake booster barb.

[818speed]

Regarding the stock fuel pressure regulator - I agree, they are generally not as stable as some aftermarket regulators and may have fluctuations in fuel pressure. You may be ok with the stock FPR but it's something that can be upgraded later if you have fueling issues. I ended up getting an Aeromotive FPR and aftermarket fuel controller since the Stealth 340 pump in the Boyd tank draws almost double the current of the OEM pump. Some people hard wire a beefier wire to the pump directly (bypassing the fuel controller), this is where the stock FPR will definitely not be able to keep up. I tried this out and ran very rich.

Installing an aftermarket FPR looks fairly straightforward. I’ll probably go with an Aeromotive one. How do you recommend I dial in the pressure?

Also, I have an iWire harness, and I think the fuel controller is an upgraded unit.

[STiPWRD]

Installing an aftermarket FPR looks fairly straightforward. I’ll probably go with an Aeromotive one. How do you recommend I dial in the pressure?

Also, I have an iWire harness, and I think the fuel controller is an upgraded unit.

The fuel pressure should be set to 43.5 (ish) psi with the vacuum source disconnected. You'll want to install a dial gauge to the FPR so you can read the fuel pressure while turning the set screw on top. Here's what I'm running:

Aeromotive Fuel Pressure Reg 13109
Aeromotive FPR Gauge 0-100 psi 15633

Great to hear iWire updated the fuel controller, you're probably all set.

[818speed]

Right on. Thanks for the suggestions.

Any idea what i should expect to pay for a good tune?

[STiPWRD]

The cost of the tune will depend on a few factors - Access port vs. open source, speed density vs. MAF, remote tune vs dyno tune, etc. Depends on what your expectations are and what tuners are in your area.

If you've got a relatively stock engine and do a remote tune, that might run $300-$400, a dyno tune may be $600-700 rough ball-park. An open source tune will generally cost more than an AP since the AP can do on-the-fly changes, then again it will cost you $500-700 for an AP. In my case, I wanted a speed density dyno tune and couldn't find a tuner in my area to do that open source so I had to break down and pick up an AP.

[Shawn818c]

This is the regulator I was looing at, not sure what is different between this one and the one STi suggested.

https://www.summitracing.com/parts/aei-13136

**edit, also summit is offering a free gauge with a FPR purchase currently.**

[818speed]

I appreciate the response STi, I had anticipated around $1000 for a tune. Not too many turners specialize in Subarus in my area, so I’ll prob go the AP route.

Thanks for the suggestion Shawn, makes my decision to upgrade that much easier lol.

Anyone know what fitting is needed to attach the fuel line from the regulator to the engine? Also, would it be advised to use SS mesh braided fuel lines?

[STiPWRD]

Anyone know what fitting is needed to attach the fuel line from the regulator to the engine? Also, would it be advised to use SS mesh braided fuel lines?

Most regulators have ORB threaded ports and come with 5/16" barb fittings. These will work with normal 5/16" rubber fuel lines found at any auto parts store. IMO it's personal preference if you want to upgrade to AN fittings and braided lines. They are certainly nicer but can also get expensive, they add up quick. For a street car, I'd use the rubber lines.

[818speed]

Thanks for the advice!

I was talking about the adapter to the fuel rail. I believe this is it: https://subimods.com/wrx/2002-2003-w...-2007-sti.html

[STiPWRD]

That'll work but you'll need another fitting to go into the 1/8NPT. I used this adapter on mine:

https://www.ebay.com/itm/16300350284...0AAOSwWHZa1aRy
20201115_133500_HDR.jpg