Underbody Fuel Line Routing

[02TurboMI]

I tried to search but couldn't find what I'm looking for.

 

For fuel delivery and return, I'm running flexible stainless steel AN hose on the underside of my car, but don't see a protected path for the lines to take from the trunk to the front. I am thinking about adding some square tube stock to beef up the chassis as well and that could add protection (run the fuel lines next to or on the side of the tube stock.

 

Who else is running stainless or rubber fuel lines underneath the car? I have a buddy who is running Earl's Vapor Guard down the tunnel (so it's protected) but that gets close to the exhaust and drive shaft.

What are you guys doing for under body fuel line routing? Pics please!

 

*Snagged this pic from elsewhere on the forum

Edited December 6, 2019 by 02TurboMI
Clarified the type of hose being used

[dlacey]

The original steel line runs along the floor against the left sill/rocker , then jinks 90degrees under the left front seat to pickup the inner edge of the left chassis rail (90degree forward) & follows that up into the engine bay. The exposed part is the part running across the floor under the left front seat...that area could be protected.

A less exposed location could be to follow the rear brake line along the insidetop of the transmission tunnel.

[PaulTWinterton]

Here's a stock pic I found on Google Images.

[Son of Marty]

If your running stainless tubing on long runs like the fuel from tank to the front of the car be sure to support it well as it is prone to work hardening through vibration and can crack. The number 1 killer of cat diesel engines is fire caused by fatigued fuel injector line.  

[02TurboMI]

1 hour ago, PaulTWinterton said:

Here's a stock pic I found on Google Images.

This is a great pic! Thanks. I'll see if I there's enough room that I can route 2x AN-6 lines along that path. I'd prefer a straighter path, but this might have to do.

 

20 minutes ago, Son of Marty said:

If your running stainless tubing on long runs like the fuel from tank to the front of the car be sure to support it well as it is prone to work hardening through vibration and can crack. The number 1 killer of cat diesel engines is fire caused by fatigued fuel injector line.  

Yeah I'm planning on welding on weld studs every 12" (may be overkill) and using standard fuel line clamps. Still debating weld studs vs rivet nuts depending on there the holes would go on the vehicle.

 

Still interested if anyone on here has experience will routing stainless AN lines from the tank to the engine.

[M3M3]

3 hours ago, 02TurboMI said:

I'll see if I there's enough room that I can route 2x AN-6 lines along that path. I'd prefer a straighter path, but this might have to do.

I run two stock steel lines on that path with no issues.

[AceAndrew]

I’m doing this right now.  Running a similar route as the oem setup pictured above (most protected).  Running welded studs with BMW oem nylon clamps and clips from e30/e28 generation cars.  Brake a fuel lines running tandem.  Tubing is Cunifer.  

Edited December 6, 2019 by AceAndrew

[NYNick]

I ran aluminum in the stock location. A little tricky to pre-bend but you kinda have to bend most of it. I used the stock metal tabs to hold it in place and also drilled a small hole through them and wried the tubing to those as well. That thing isn't going anywhere.

 

I was very pleased with myself when I finagled that bent tubing from the rear of the car to the front with the rear subframe already in place. It was a F*&k Yeah moment.

[02TurboMI]

1 hour ago, AceAndrew said:

I’m doing this right now.  Running a similar route as the oem setup pictured above (most protected).  Running welded studs with BMW oem nylon clamps and clips from e30/e28 generation cars.  Brake a fuel lines running tandem.  Tubing is Cunifer.  

Are you using flexible AN hose for the fuel lines?

[02TurboMI]

I updated the OP to clarify: I’m using flexible stainless steel AN hose (Earl’s Ultrapro) for both fuel delivery and return.

[TobyB]

Ok, for further clairityificationism:

 

 you're running a RUBBER hose with a braided stainless jacket and embeddinated stainless layer?

 

Or a NYLON tube with a braided stainless jacket cover?

 

Or actual stainless line n 3/8" (AN-6 sized)?

 

Because all 3 of those are possible.

 

Personally, I use the routing close to what Paul posted, but with detail changes to give extra clearance

in places.  The E30 routing's a very good guide on what the factory thought would work, as the E30

chassis has almost all of the 'features' that make routing on the 2002 a non- trivial task.

On the race car I took it through the cabin, along the tunnel- because it's far less likely to 

spontaneously pop than I am to beat the underside to hell on the curbing.

 

t

likes 3/8" stainless tube with silver- soldered AN-6 to mate to the AN-6 flexible rubber stainless- jacketted hose he uses

to hook to the fuel pump and the carbs.

phew.

that's a mouthful.

 

hee

 

 

 

[Mike A]

No experience with racing the 02, but after prepping a few 911s I question the Fuel line in the cabin. Why not the tunnel?  ....exhaust heat?

Edited December 6, 2019 by Mike A

[xr4tic]

Re-consider using braided rubber line.  It will eventually start leaking as the rubber deteriorates and it's not cheap to replace.

 

I'm going to run 3/8" Ni-Copp tubing for feed/return, following the original hard line.

[TobyB]

2 hours ago, Mike A said:

No experience with racing the 02, but after prepping a few 911s I question the Fuel line in the cabin. Why not the tunnel?  ....exhaust heat?

Quote

 

 because it's far less likely to 

spontaneously pop than I am to beat the underside to hell on the curbing.

 

 

[Son of Marty]

If your determined to run hose instead of metal tubing you'd be much better off in the long run to use the style of hose with the stainless armor buried under a rubber jacket for a couple of reasons such as the stainless braiding will rub through anything it comes in contact with and running under the car fine road grit will shortly work it's way under the braiding and start wearing at the soft under-hose and there's no way to inspect the condition of the hose with out cutting it in half.