Running hard lines through trans tunnel

[jeskam]

Any reason not to? It's a well protected area. I won't have an e-brake or associated hardware/lines on that side. In the interest of keeping the lines as straight as possible with as few bends as possible and as little north south travel it seems like a winner yet I can't find any previous posts concerning this particular plan.

[Mike.Bray]

In theory it's not a good idea to have fuel or brake lines close to a rotating part like a driveshaft that could fail. Maybe a bit of a reach but stranger things have happened.

[BEAR-AvHistory]

Agree with Mike. Even with a drive shaft loop it's not a good plan to put the lines in there. Just something extra to get in your way when you change a clutch.

[GoDadGo]

I've got my fuel line (3/8") run on the outside of the 4" round tube from the tank to the mechanical fuel pump.

[Al_C]

I asked the same question during my build, and everyone agreed it was a bad idea. My lines run outside the 4" tube like GoDad's. I'd recommend you follow his lead.

[Jim1855]

OK, so I don't follow the crowd, jeez I barely read the book.

I'll have fuel, brake and electric between the main frame tubes. I feel it's far better protected between than outside the tubes. BTW, the Gen 3 coupe runs the lines through the trans tunnel. Added through holes to the rear cross tube on both sides for pass through access otherwise the lines would need to go over or under the cross tube.

Fuel feed and brake & clutch lines will be on the driver's side, fuel return and electric on the passenger side. Built a circular, heavy wall driveshaft hoop that is almost as long and the driveshaft and sized to actually control the driveshaft in case of a failure. The hoop is placed in the middle of the 5.25" u-joint to u-joint driveshaft.

Also built a diff mounted parking brake disk and caliper mount.

Jim

IMG_6005-1.jpgIMG_6008-1.jpgIMG_6009-1.jpg

[GoDadGo]

OK, so I don't follow the crowd, jeez I barely read the book.

You asked a question & folks like me responded.
As for me I am NOT automotive expert nor do I claim to be.

Good Luck!

[Papa]

Traditional wisdom seems to say not a good idea, but those building Coupes have no choice without having things hanging below the frame.

[BEAR-AvHistory]

Hi Jim,

Good to hear about your all most "Torque Tube" to protect your driveshaft from becoming a lethal weapon. Thing is outside of a few of us I would bet a very small percentage of these cars even have a loop.

Also like me I expect a lot of the builders have gone there own way on specific items. That what makes this whole thing so interesting. Lots of different opinions here.

That said s--t happens.

[michael everson]

I run all my fuel lines up high in the tunnel. Like someone else pointed out, you have no choice in the Coupe. In
My opinion it’s much more likely that something in the road could damage the fuel
Lines than a failed driveshaft.
Mike

[BRRT]

Hi Jim,

Good to hear about your all most "Torque Tube" to protect your driveshaft from becoming a lethal weapon. Thing is outside of a few of us I would bet a very small percentage of these cars even have a loop.

Also like me I expect a lot of the builders have gone there own way on specific items. That what makes this whole thing so interesting. Lots of different opinions here.

That said s--t happens.

Damn Kevin, that's a mess

[OB6]

I run all my fuel lines up high in the tunnel. Like someone else pointed out, you have no choice in the Coupe. In
My opinion it’s much more likely that something in the road could damage the fuel
Lines than a failed driveshaft.
Mike

Mike, you do this on Coupes and Roadsters? I may go with under-car exhaust, so running the fuel line in the tunnel would help keep it away from the Hot exhaust system.

[michael everson]

Yes both coupe and roadster.
Mike

[cc2Arider]

I've thought about this for some time, too, because fundamentally the mechanicals are identical between the Coupe and Roadster, yet the lines are typically mounted in the tunnel for the Coupe...

After thinking it through and considering my skills at the moment, I decided on the "traditional" routing for my Roadster. What I'm planning to do to protect the lines from road debris is to add stainless wire wrap (tubing guard) like this https://www.summitracing.com/parts/ops-gg3816ss

Craig C

[edwardb]

I've thought about this for some time, too, because fundamentally the mechanicals are identical between the Coupe and Roadster, yet the lines are typically mounted in the tunnel for the Coupe...

Craig C

Front and rear suspension are the same. Other than that, really very different. The Gen 3 Coupe has the space frame. There are rails completely across the bottom of the frame front to back. As someone stated, not possible to run fuel, brake, or power other than through the tunnel without having them below the frame. Which would be even higher risk. Not the best picture. But shows how different the Gen 3 Coupe chassis is to the Roadster. I have the front to back runs at the top of the tunnel and a driveshaft safety loop.

[skidd]

Whenever ever pulling and installing a trans, and often motors too. Or, even as an all-in-one unit. It's common for the trans to bump and press against the sides and top of the trans tunnel. Even with a decent amount of force if you use a floor jack.

For that reason alone, I would avoid brake and fuel lines in the tunnel.

My 02c

[rich grsc]

Have had many engine and transmission R&R, never have I ever hit the frame hard enough to even scratch the finish. No danger the fuel or brake lines, and it's not a common thing to hit the frame.

[JohnK]

I also agree with Mike. The chance of a driveshaft failing and damaging brake or fuel lines in the trans tunnel may be very small but it's not zero. IMO, the lowest-risk choice is the best choice. On the coupe the only other choice is to run lines under frame members, which is higher risk than running them in the trans tunnel. On the roadster, where you can run them on the outside of the 4" tubes, I don't see a good reason to choose to run them through the trans tunnel.

[OB6]

I went out to the garage to take a look. Safety concerns aside, running through the tunnel looks like more of a pain than I want to deal with. I also like Skidd's point about the risk of hitting lines when R&Ring the drivetrain. I thought I might try running it in the tunnel, but nope.

[Alan_C]

I ran my braided flex fuel lines in the tunnel, no concern at all. However, I did install Forte's driveshaft safety loop. I did not think the DS, even if broken, could hit my fuel lines.
The flex lines, IMO, are less likely to be burst than hard lines. The flexible material provides some resilience that hard lines cannot.
All of my nickel copper brake lines were run along the outside of the frame rails.
Do what makes sense to you as long as you don't run a critical line or cable right next to rotating parts of the car.

[Sarcasticshrub]

What I'm planning to do to protect the lines from road debris is to add stainless wire wrap (tubing guard)...

I'm assuming you are not using the kit-provided tubing but bending your own? It would be the only way to use tube armor like you are planning unless you cut off one of the already installed ends to slip the armor on. If not, and if you haven't already purchased the tubing and armor, I recommend going directly to The Stop Shop for both.

Running brake/fuel lines traditionally on the outside works and does not look half bad.

Fuel.Lines.jpg

[cc2Arider]

Yep Sarcasticshrub, I am building my own lines

@EdwardB, what I meant by the mechanicals being fundamentally identical was everything EXCEPT the frame

Craig C

[CraigS]

Another thought from production body based race cars. They often run fuel, brake, electrical front to rear through the interior through a steel tube. To simplify my explanation, think about a tube 1-1.25". Drill a hole in the firewall, drill a hole in the rear cockpit wall, slip the tube through both holes and weld to each wall. Of course in this case the walls are steel, and they also bend the tube to get it out of the way, but the concept still applies. It would be fairly easy to put a steel tube into a corner of the trans tunnel. One could also place it in the cockpit on the floor outside of the seat against the X bracing under the door.

[drewr]

I have a Coupe as well and ran the lines through the tunnel just as the manual says. I have a drive shaft safety loop installed. Having the lines in the tunnel is just one of the small ways these cars can kill you. "You pays your ticket, you places your bet." As a physician I spend most of my time trying to explain probability and risk to patients. Some risks are more likely to occur, some less likely. While it is not impossible that a drive shaft failure could tear the lines and start a fire, it is less likely than you getting T-Boned by some idiot running a red light. I suspect that if absolute safety was paramount to you, you wouldn't have picked a Cobra that your were required to build.

[Tooth]

FFR instructions for the coyote has you run braided lines through the tunnel in the roadster.

[michael everson]

Finally, someone said it. Wanna bet the regulator mounted on the firewall poses a much greater risk than fuel lines in the tunnel?
Thanks drewr

[JohnK]

One needs to be able to differentiate between avoidable risks and unavoidable risks. On motorcycle forums you often see debate about ATGATT (all the gear, all the time). A similar argument is often used: "motorcycling is inherently risky, and if you're not comfortable with it you shouldn't be riding a motorcycle." True enough, you could be in full leathers and be taken out by some idiot making a left turn. That doesn't make riding around in a t-shirt and flip-flops a good idea. We should all be comfortable with the unavoidable risks we're taking on when building and driving one of these cars. That doesn't mean we should ignore the avoidable risks. Otherwise, hell just run some rubber hose from the fuel tank through the cockpit and call it good enough, right?! After all, these cars are dangerous.

[edwardb]

[rich grsc]

Butter, or no butter?

[OB6]

Jus so the popcorn doesn't go to waste...

I got my Aeromotive fuel regulator mounted last night, just forward of the tank on the 1" tube. I have to say, that location sure makes for a direct and short run to the engine bay through the tunnel -- with either a single braided or hard line. Hmmm...