Teaser: DIY stage 4 fuel system

veer90

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Nov 16, 2016
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Really nice post Veer90.
Like you I decided to do my own dual pump system but I don't fully understand the FPR side of things so I've left my second pump disconnected for now.
I've looked at your setup and I'm afraid I still don't fully understand it. I want to make sure I don't blow a fuel line off, starting a fire.

My port meth setup is flowing lots of fuel. More than enough for my current requirements but in the future I'd like to have a direct injection only setup.
Once there's a hpfp solution.

I see that often a fuel pulse damper is fitted to systems like these to make the fuel pressure more stable. Avoiding peaks and troughs in pressure. Not sure how pressure looks when the second pump kicks in and turns off.

If you're concerned about overpressure the easiest way would be to add an aftermarket FPR / return line and deleting the stock FPR on the fuel sender.

I'm not sure on your exact question or setup. Fuel and power goals?
 

Mikejones1208

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Dec 6, 2016
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Thanks for the tip @veer90 , found a bulkhead fitting thats 6an on the top side and 5/16 barbed on the bottom, didnt go all out like you but i atleast bypassed the shitty in tank filter and now run a russel inline filter that can be serviced easily!

IMG_20190125_192044.jpg

IMG_20190125_191237.jpg

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veer90

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Mikejones1208

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Oh yeah easily, it actually sits below the ledge so the cap doesnt even touch it
IMG_20190125_195548.jpg

IMG_20190125_195601.jpg

That second pic is a side profile with the 90 attached, i didnt even thread it all the way down, so it actually should it sit a little lower
 

fmorelli

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Thanks for the tip @veer90 , found a bulkhead fitting thats 6an on the top side and 5/16 barbed on the bottom, didnt go all out like you but i atleast bypassed the shitty in tank filter and now run a russel inline filter that can be serviced easily!
Nice work. It's funny how topics are a matter of perspective. On the E89 there is one fuel tank access hole. It''s under the car. Drop the rear exhaust, heat shield, unravel the fuel lines to the fuel housing, empty the tank (good luck - two humps, never clear which one is being drained - murphy's law, not the one you want drained, and then even after it is drained, it is never completely empty so it is just going to piss all over you). Then ... in the hole is the filter, and then further inside (go ahead and reach in) is the LPFP. I'd kill to have 5 minute access to a fuel filter and LPFP under a seat, a few plate bolts, and a quick twist of a screw top lol! I'm not sure if that filter is actually shitty? It protects the LPFP I suppose and reduces filtration for the later, finer HPFP filter. Is the Russell, likely installed under the car, easier to service than the in tank filter?

Nice work! I'm just generally envious :p

Filippo
 
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rac

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how is everyone using hydramats securing them to the base of the tank?
does anyone have dimensions of the available space for hydramats either side of the tunnel?
 

Mikejones1208

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Nice work. It's funny how topics are a matter of perspective. On the E89 there is one fuel tank access hole. It''s under the car. Drop the rear exhaust, heat shield, unravel the fuel lines to the fuel housing, empty the tank (good luck - two humps, never clear which one is being drained - murphy's law, not the one you want drained, and then even after it is drained, it is never completely empty so it is just going to piss all over you). Then ... in the hole is the filter, and then further inside (go ahead and reach in) is the LPFP. I'd kill to have 5 minute access to a fuel filter and LPFP under a seat, a few plate bolts, and a quick twist of a screw top lol! I'm not sure if that filter is actually shitty? It protects the LPFP I suppose and reduces filtration for the later, finer HPFP filter. Is the Russell, likely installed under the car, easier to service than the in tank filter?

Nice work! I'm just generally envious :p

Filippo

The intank filter is one of the biggest restrictions in the fuel system and cant be serviced at all, its one of those "lifetime" filters, only thing you can do is change out the entire assy which costs 170-200 bucks for a replacement, the russel is under my car and a filter replacement costs only 5, and once under the car its just 2 an fittings i unscrew then the filter is in my hand. So by doing what i did i bypassed a big restriction and made servicing the filter cheaper and quicker.
 
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Mikejones1208

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Nice work. It's funny how topics are a matter of perspective. On the E89 there is one fuel tank access hole. It''s under the car. Drop the rear exhaust, heat shield, unravel the fuel lines to the fuel housing, empty the tank (good luck - two humps, never clear which one is being drained - murphy's law, not the one you want drained, and then even after it is drained, it is never completely empty so it is just going to piss all over you). Then ... in the hole is the filter, and then further inside (go ahead and reach in) is the LPFP. I'd kill to have 5 minute access to a fuel filter and LPFP under a seat, a few plate bolts, and a quick twist of a screw top lol! I'm not sure if that filter is actually shitty? It protects the LPFP I suppose and reduces filtration for the later, finer HPFP filter. Is the Russell, likely installed under the car, easier to service than the in tank filter?

Nice work! I'm just generally envious :p

Filippo
Sorry for the late reply but im re reading this and i think you meant the fuel pump strainer (filter that attaches to the bottom of the pump itself) that is still present and attached the pump, what im referring to is attached to the bottom of the hat on the driver side. Thats the one i bypassed that is a restriction
 

veer90

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Updates are slow since it's winter here and I low key wanna die every time I go work on my car. But my dumb ass managed to fry the EKP this weekend.

I tried a new design for the harness and the EKP did not like it. Despite the fact I had a diode wired in line, power from the battery must have back fed somehow and fried it. However the rest of the EKP seems to be working perfectly fine - the car "sees" the fuel pump, it just can't power it - no yellow "service needed" car on lift icon in the cluster, only a DME fault code (that can be disabled): CDA6 - Message (status, electric fuel pump, 0x335) faulty, receiver DME, transmitter EKP.

This actually worked out, as I had originally planned hard wiring both pumps anyways. Rewired the relay to ignition switched using the cigarette lighter fuse in the glove box, added a kill switch for the pumps in the armrest storage space so I don't kill the battery while flashing tunes, and all is well.

Here's the circuit:

stg4 wiring_cr.PNG

As installed:

20190126_223827_copy.jpg 20190126_223859_copy.jpg 20190126_223907_copy.jpg 20190126_004536_copy.jpg
 
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Mikejones1208

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@veer90 Thanks for the thread. My setup is fuelit stage 4 with 6 micron external filter, all fuel lines upgraded, external FPR, Pi etc.

I decided to keep the stock connection for the filter bypass instead of using bulkhead fittings. Thanks again. View attachment 22291
Mind sharing some pics of how you bypassed the stock filter while retaining the factory feed connection! Id prefer to do it that way down the road!
 

Twinz

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A dremmel & patience. I cut up a few hats before to understand the restrictions...so the bypass was all part of the fun. The stump to connect the corrugated fuel hose to is not very long but enough to fit a clamp solid around it or one can dremmel away another inch or so for more clearance. I heat up the fuel line to push it over and while it was still warm clamp it down. The connection
IMG_20190201_171317.jpg
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IMG_20190201_145623.jpg
felt pretty tight and solid.
 

veer90

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That's great, definitely save a lot of headaches for anyone doing this if they can simply remove the paper filter and there's a barb inside.

Like I said, the hardest part was making the whole thing fit. This way is much cleaner.
 
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R.G.

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Don't use brass fittings
24564
 

Attachments

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R.G.

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what kind of incompatibility are we talking? if it's just surface corrosion I should be fine lol

Puts on fake scientist coat

Probably fine, you're like "N54 guy #194" who's done that. Just for reference to others who want to tackle the project.

Next time you open the tank up I'd swap it out.

McMaster-Carr has what is needed

 

veer90

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Puts on fake scientist coat

Probably fine, you're like "N54 guy #194" who's done that. Just for reference to others who want to tackle the project.

Next time you open the tank up I'd swap it out.

McMaster-Carr has what is needed


If you have evidence of brass fittings corroding through or causing fuel system damage I would love to see it. Serious, not trying to be a dick.

I chose brass based on a different chemical compatibility sheet: http://catalog.gpi.net/Asset/Chemical-Compatibility-Ver-6.pdf

Lists brass as "recommended" for ethyl alchol and most hydrocarbons.