Stock fuel line diameter and material?

[jvictormp]

I'm away from home, could anyone help me find out what's the outside diameter and the material of the fuel feed line?

I'm refering to that coming from tank, going below the car and reaching the fuel rail in engine bay.

That's because I'm installing an inline fuel filter and need to make a good connection in the line below the car.


Thanks.

[Harryc9]

Any updates on this?

[jvictormp]

Originally Posted by Harryc9

Any updates on this?

Unfortunately, there is no room for a filter below the car, because it will become the lowest surface of the car, and there is risk of hitting it in ondulations, speed reducers, etc.

There's only one place right next to left front wheel well, below the column, but it wouldn't stay aligned to the fuel line, so there would need to be two curves, which I thought I'd wait a little before doing, because that can cause loss of charge (pressure), and I was just putting the new engine on the car and wouldn't like to have any unexpected obstacles on running engine.

I'll post some photos.

[Harryc9]

Nice work, this is a harder job than I first thought too haha. Hope the engine installation goes well.

[Harryc9]

I've seen this kit advertised (called: E9X M3 S65 Inline Fuel Filter Kit):

https://www.nrw-design.com/products/...uel-filter-kit

I think this is the best option I have for cost, ease of servicing and installation.

The only caveat is that on our UK facebook forum, one guy (while tracking the car) said his got really hot. Therefore, I plan to fit some of this: FUNK GOLD REFLECTIVE HEAT TAPE (from Funk Motorsport) to reduce the heat absorbed by radiation of the black Aluminium housing (I don't track my car atm).

Another bit of information recently from the UK facebook forum; Carbon deposits might be building up on the injectors. But I don't know how reliable this information is. Could anyone else comment? I may use injector cleaner a bit more frequently if Carbon build-up is occurring in normal use.
Thanks all

[jvictormp]

Originally Posted by Harryc9

I've seen this kit advertised (called: E9X M3 S65 Inline Fuel Filter Kit):

https://www.nrw-design.com/products/...uel-filter-kit

I think this is the best option I have for cost, ease of servicing and installation.

The only caveat is that on our UK facebook forum, one guy (while tracking the car) said his got really hot. Therefore, I plan to fit some of this: FUNK GOLD REFLECTIVE HEAT TAPE (from Funk Motorsport) to reduce the heat absorbed by radiation of the black Aluminium housing (I don't track my car atm).

Another bit of information recently from the UK facebook forum; Carbon deposits might be building up on the injectors. But I don't know how reliable this information is. Could anyone else comment? I may use injector cleaner a bit more frequently if Carbon build-up is occurring in normal use.
Thanks all

Hi Harry.

Just tried to reach you this week at M3cutters.

Take a look at this thread:

https://www.m3post.com/forums/showthread.php?p=31113249

Yes, NRW solution appears to be good.

Seems leak-proof, which keeps things safe even when filter sits above exhaust header.

About heat absorption, in my solution, that places filters in the front of the engine, I can confirm they get hot, but doesn't get hotter than hoses and lines got earlier. Only difference is when you compare by touching them, because rubber hoses have lower "thermal conductivity coefficient" than aluminum, so that they don't seem to be so hot when you touch. And when you touch aluminum, it seems pretty hot. But all of them are staying about 50/122 ºC/ºF or 60/140 ºC/ºF. I don't see a problem there. Sure you can wrap in a reflexive tape, but after a while of engine running, everything will come to a thermal equilibrium and sit at the same 50 ~ 60 ºC.

Also, NRW took a good step relocating the pressure sensor to after the filter. EuroPowerMotorsport is offering a filter too, but doesn't relocate the pressure sensor.

That may be dangerous, because if the pressure drop in the filter gets too high, ECU will be blind and may have trouble regulating mixture or even protecting the engine against lean mixture scenario.

[jvictormp]

Originally Posted by Harryc9

I've seen this kit advertised (called: E9X M3 S65 Inline Fuel Filter Kit):

https://www.nrw-design.com/products/...uel-filter-kit

I think this is the best option I have for cost, ease of servicing and installation.

The only caveat is that on our UK facebook forum, one guy (while tracking the car) said his got really hot. Therefore, I plan to fit some of this: FUNK GOLD REFLECTIVE HEAT TAPE (from Funk Motorsport) to reduce the heat absorbed by radiation of the black Aluminium housing (I don't track my car atm).

Another bit of information recently from the UK facebook forum; Carbon deposits might be building up on the injectors. But I don't know how reliable this information is. Could anyone else comment? I may use injector cleaner a bit more frequently if Carbon build-up is occurring in normal use.
Thanks all

Ah, and about carbon buildup, I can't imagine where that would come from.

What I can imagine and co-relate with another theory, is that the pump strainer (which a filter that is not serviceable) may be desintegrating and sending crap through the line, and that may get to the injectors. That would also be easily caught by a 10-micron filter, though.

[Harryc9]

I think you've spotted the main misconception: Aluminium has very high thermal conductivity, so people who haven't considered this think it's much hotter than the surrounding parts when doing a 'touch-test' (not the case).
The fuel flowing through the filter body acts as a coolant too, so if radiation is the dominant mode of heat transfer (plausible near the exhaust in an engine bay) then reflective tape would be a good solution.

RE Carbon build-up - fuel has plenty carbon in it obviously, but I have no idea why it would crystallise in the injector - need to do more research to find out if frequent injector cleaner usage is necessary.

I think your hypothesis of broken pieces of fuel strainer from the tank passing through the pump makes sense - I wonder if any debris has been tested.

I'm excited to fit the fuel filter and not worry when my tank starts to get down to 1/4 full (currently I never let it go below a quarter through fear of injector failure).

Keep up the good work my friend and enjoy the M3.