With a few modifications, even a stock Vulcan exhaust can have a deeper sound.
Kawasaki’s Vulcan cruiser motorcycles are powered by a V-twin motor that can be easily mistaken for American iron. Unfortunately, the roar of the Vulcan’s motor is dulled by the baffles placed in their mufflers to comply with strict emissions regulations, leaving most Vulcan owners to resort to expensive aftermarket pipes to regain that deep exhaust note. However, modifications can be made to the VN 900 and 1600 models to remove the baffles, increasing the sound of the exhaust note at a minimal cost. Be warned that this modification may void your warranty and gain unwanted attention from law enforcement.
End Cap Modification (Vulcan 900)
1. Drill out the rivets from the muffler’s end cap with an electric drill and remove the end cap. Trim the flange that the end cap was mounted on a rotary tool with a metal cut-off wheel to provide access to the exhaust pipe.
2. Cut the exhaust pipe midway between the end cap flange and the inner baffle with a saber saw.
3. Use a 3/16-inch drill bit to drill four to six pilot holes on the face of the inner baffle, spacing each hole equally apart. Enlarge the holes with a bigger drill bit as desired. In most cases, the exhaust note increases in volume with larger holes.
4. Repeat on the remaining muffler. Start the motor and listen to the exhaust note. Enlarge the holes in the inner baffle or add more as desired to increase the volume of the exhaust note.
Internal Modification (Vulcan 1600)
5. Loosen the muffler’s exhaust clamps with a flat screwdriver. Remove the muffler’s from the motorcycle and set them on a workbench.
6. Use a 1 3/16-inch bi-metal hole saw to cut out the the metal baffle plate from the muffler’s header-side inlet pipe. Stop cutting immediately after the baffle plate has been penetrated to prevent damaging the catalytic converter.
7. Attach the hole saw to a 24-inch extension and insert it into the muffler’s outlet pipe. Cut through the first baffle plate and withdraw the hole saw. Pull out the cut baffle piece from the hole saw. Reinsert the hole saw into the muffler and cut into the third remaining baffle plate Stop cutting immediately after the baffle plate has been penetrated to prevent damaging the catalytic converter.
8. Us a 3/16-inch drill bit to drill six to pilot holes into the muffler’s end cap around the outlet pipe. Space each hole equally apart from each other. Enlarge the holes with a bigger drill bit as desired. In most cases, the exhaust note increases in volume with larger holes.
9. Reinstall the mufflers onto the motorcycle and tighten the exhaust clamps with a flat screwdriver. Start the motor and listen to the exhaust note. Enlarge the holes in the inner baffle or add more as desired to increase the volume of the exhaust note.