Fuel line routing dos and donts?

[absintheisfun]

I finally have everything ready to run with the last step being routing fuel line. I'm using a vaporworx controller, so single line. I'm trying to minimize flex line to a foot near the tank and a foot near the engine with solid 3/8 the rest of the way. So the questions...

1. Inside the frame rail seems the safest, but would it be okay/safe/allowed at races if its outside the framerail but inside the pinch weld?

Because

2. How close is too close to exhaust?

Inside the framerail would put the line within 2 inches of the muffler and about 6 inches from a few points in the exhaust and closer to the header collectors. I could probably run heatshielding at some points, but wanted to see what yall have done and had some success with.

[andrewb70]

I don't believe that there are any requirements to run fuel lines in an enclosed area. Modern cars have exposed fuel lines under the car.

Two inches is plenty of air between the exhaust and the fuel lines.

Stay away from the forged fittings that have a hard 90 degree bend. Make the bends as smooth and as big of a diameter as possible.

Andrew

[CarlC]

"Inside" can mean two different locations.

Inside 1: On the "inside" of the frame rail towards the center of the car.
Inside 2: "Inside" the hollow of the frame rail.

From a practical standpoint, I am not a fan of running the fuel line inside the hollow/enclosed frames. Though the protection thing sounds great, what happens if there is a leak? Fuel can pool inside of the frame, and that can lead to many bad things. No OEM that I'm aware off encloses the fuel line inside of an enclosed space external to the tank.

Having a longer flex line is a good thing for several reasons. First, short lines tend to be stiffer than longer, and with the fuel outlet on the module being plastic, a longer line tends to apply less strain/less tendency to break. The other is accident safety. Having a longer flex line allows for more movement without possibly tearing out a short flex line. Also, it is usually a bit easier to have the flex ==> hardline connection on the frame rail where there may be more room for a support system.

Unless the car is a rocketship I doubt most NHRA inspectors are going to hassle you if the fuel lines are run in the stock locations/outboard side of the fuel rail.

[79 Camaro]

As said above I would go with longer flex line just ease of access. I actually run flex line from front to back. That eliminates any extra couplers. Use rubber insulated line clamps every 12" or so.

[absintheisfun]

Inside meant inboard of the frame rail, not actually inside the frame. I'll make a gametime decision on location and routing when I'm under the car tomorrow.

I can get behind longer flex lines, I just thought that there were requirements with some racing groups minimizing the total amount of flex. While I may not necessarily plan on racing where those rules exist, it seems to make some safety sense.

Coming off of the pump I actually have a bung welded to the tank to secure the hardline to the tank so there is zero movement in the hard line coming off the tank.

All my lines and fittings came in today, so wish me luck for getting it all run tomorrow!

[JohnUlaszek]

Hose manufacturer’s will often list a maximum sustained temp and a short duration temp. I’d cover the hose with reflective covering near heat sources where you think you might have a problem.