Charcoal Canister Notes: B-Body Mopar (Charger, Road Runner, Coronet, Super Bee)

The B-body is the mid-size Mopar: Charger, Road Runner, Coronet, Super Bee, and their relatives. If yours leaves the garage smelling like gas, the fix is the same as on any classic: catch the vapor on the tank vent line with a Vapor Trapper™. Running a smaller Mopar? See our A-body Mopar notes.

Start with what your car has now

Year, market, and decades of restoration work all change what's on a B-body today. Before you buy parts, find out:

• Where the tank actually vents. Follow the vent line from the tank or filler neck. Is it open to air, plumbed to an old canister, or capped off?
• Whether there's an old canister. If the car has one, check whether it's cracked, empty, or disconnected. The Vapor Trapper takes over the job of catching vapor on the tank vent line.
• The gas cap. A vented cap is still an open path for vapor. Switching to a non-vented cap, or plugging the vent in your existing one, is the cleanest finish. Our post on charcoal canister vs. vented gas cap explains how the two work together.
• Filler-neck vent. If you pick up the vent at the filler neck, that's what our brass 3/8" hose barb x 1/8" NPT 90° elbow is for.

What to watch for

• Mount high. Put the canister as high above the fuel tank as you can, away from excess heat and moving parts. On most cars, the area under the rear package tray is ideal.
• 8" vent-line rise. The vent line should rise at least 8" above the gas tank before it reaches the canister. That keeps liquid fuel out of the charcoal during hard launches, braking, and fuel slosh.
• Any orientation. The Vapor Trapper can be mounted vertical, horizontal, or upside down.
• Can't get the height? The Fuel Stopper limits how far fuel surges up a short vent run. The Surge Tank catches liquid fuel when the canister has to sit low.
• Tight on space or want a flat mount? The Low-Profile Vapor Trapper™ mounts directly to a flat surface.
• High-flow fuel system with a 1/2" vent line? The High Performance Vapor Trapper™ (6" or 8", -8 AN end caps) is built for larger vent lines. Go by your existing vent-line size, not horsepower alone.
• Outlet. Leave the canister outlet open and unobstructed. If it's mounted in the trunk, run the exit line to the outside of the car.

Which canister size?

Shop48 recommends the 8" if it fits, for the most charcoal. The 6" gives the same results where space is tight. See the sizing guide.

For the actual installation steps, see the universal Vapor Trapper installation guide. The procedure is the same across vehicles. Only the routing and mounting change.

Building something specific or unsure about routing? Contact us with a few photos of your tank area and where you'd like to mount it, and we'll help you spec the right setup.

VaporCanister.com is an authorized retailer of the Vapor Trapper™ by Shop48.