dannenvance
Well-known member
- Joined
- Jun 6, 2012
- Messages
- 216
I recently finalized my muffler chop and got it installed on the bike. I really love the end result so I’m posting the process to show what I’ve done.
I was primarily motivated by the amazing V-8’y sound of the Hawk pipe but wanted to see if I could do something of my own design. Being a diehard fan of the look of the original muffler I wanted to keep that as the overall aesthetic, just give it a little more visual detail and that lower, slightly louder rumble without being obnoxiously loud.
For consistencies sake I’m calling the exhaust inlet/adjustable-valve end the ‘front’ or ‘head’ and the outlet end the ‘back’.
Using a Dremel tool and 1” tape line I chopped through the can about an inch behind the embossed “JACKPOINT” spot and then used a hack saw to cut through the interior pipe which runs through the end cap. If you have access to a band saw (which I didn’t) that’ll do it all at once.
Now you have the exposed rear-end of the muffler baffle tubes. From here I drilled perforation holes all around the circumference of the inside of the muffler. I then used a jig saw to ‘disconnect’ the baffle tubes from each other and also went around the perforation holes to release the rear of the can from the baffles.
Next I used the Dremel and another tape line to cut through the can just IN FRONT of the BACK chin fairing bracket. I recommend getting the cut line as close to the bracket as possible which you can see here in the exploded view. Now the can will just slide off leaving the baffle tubes exposed.
Again, using the Dremel I chopped off the baffle tubes leaving only about a ½ inch of the tube remaining protruding through the ‘head wall’. The rear end cap/exhaust outlet and the baffle tubes get tossed. What’s left is the head and the can exterior.
Considering that I did want SOME baffling inside but with a still ‘free-flowing’ design I went about making my baffles to weld to the interior of the can. I stood the can upright on a piece of paper so that the edge of the paper covered approximately the top 60% of the volume of the can (in terms of diameter) and traced the interior curve (the picture below makes it look much less due to perspective). This was to be my center baffle. I then did the same thing twice more but with the paper covering the bottom 60% of the volume of the can, these were to be my front and rear baffles. Wanting to make sure my front baffle wasn’t too restrictive I drilled one large hole (approx 1 ¼”) in the middle and two smaller holes on each side (approx 5/8”).
The end result is a baffle at the front of the can causing the airflow to slow down, split and partially tumble over the front baffle. The air is then forced to the bottom of the muffler via the center baffle and then forced upwards again via the rear baffle before exiting the dual tips.
I then welded the can with the new baffles on to the head and welded in a recessed end cap and drilled my dual exhaust outlet holes with a 2 ¼” hole saw. For added strength I welded a band around the circumference of the muffler at the spot where the can and ‘head’ went back together.
I purchased one set of stainless Corvette C6 exhaust tips off ebay for $25.
When they arrived I cut them at mirroring angles near the center split and ground them to the shape I needed for the right look. I then polished them (thanks again Dremel) and had my neighbor weld the tips on the muffler end cap for me since he has access to a stainless welder.
Since my driveway has fairly sharp transitions at each side causing a steep angle and the fact that my bike is a CG therefore lower than usual I’ve had a couple minor scrapes on the bottom of the muffler. To protect the underside of the muffler going forward I welded two 18 inch long, ¼ inch round hardened steel ‘runners’ just off the centerline of the muffler.
I then prepped and painted the muffler with 2000 degree flat black exhaust paint and reinstalled it.
Here’s the final look on the bike…
I’ve only ridden it about 60 miles since reinstalling but the sound is absolutely amazing with a nice low rumble and louder than stock without being TOO loud. I didn’t want it to sound like a Harley and there’s no chance it was going to sound like the typical I-4 sportbike, now it just sounds like… mine. I couldn’t be happier with the look as well; the dual Corvette tips are proportionately the absolute perfect tips.
Performance-wise it does feel a bit snappier through the entire band and so far I haven’t had the engine light come on. I suppose I’ll be purchasing a race ECM before long since that’s what I’ve read in countless posts regarding switching out mufflers but so far all is fantastic. There is occasionally very minor popping on decel but again it’s very minimal, nothing loud, and honestly it makes it sound a bit nastier which is sorta cool.
Comments welcome…
Thanks.
I was primarily motivated by the amazing V-8’y sound of the Hawk pipe but wanted to see if I could do something of my own design. Being a diehard fan of the look of the original muffler I wanted to keep that as the overall aesthetic, just give it a little more visual detail and that lower, slightly louder rumble without being obnoxiously loud.
For consistencies sake I’m calling the exhaust inlet/adjustable-valve end the ‘front’ or ‘head’ and the outlet end the ‘back’.
Using a Dremel tool and 1” tape line I chopped through the can about an inch behind the embossed “JACKPOINT” spot and then used a hack saw to cut through the interior pipe which runs through the end cap. If you have access to a band saw (which I didn’t) that’ll do it all at once.
Now you have the exposed rear-end of the muffler baffle tubes. From here I drilled perforation holes all around the circumference of the inside of the muffler. I then used a jig saw to ‘disconnect’ the baffle tubes from each other and also went around the perforation holes to release the rear of the can from the baffles.
Next I used the Dremel and another tape line to cut through the can just IN FRONT of the BACK chin fairing bracket. I recommend getting the cut line as close to the bracket as possible which you can see here in the exploded view. Now the can will just slide off leaving the baffle tubes exposed.
Again, using the Dremel I chopped off the baffle tubes leaving only about a ½ inch of the tube remaining protruding through the ‘head wall’. The rear end cap/exhaust outlet and the baffle tubes get tossed. What’s left is the head and the can exterior.
Considering that I did want SOME baffling inside but with a still ‘free-flowing’ design I went about making my baffles to weld to the interior of the can. I stood the can upright on a piece of paper so that the edge of the paper covered approximately the top 60% of the volume of the can (in terms of diameter) and traced the interior curve (the picture below makes it look much less due to perspective). This was to be my center baffle. I then did the same thing twice more but with the paper covering the bottom 60% of the volume of the can, these were to be my front and rear baffles. Wanting to make sure my front baffle wasn’t too restrictive I drilled one large hole (approx 1 ¼”) in the middle and two smaller holes on each side (approx 5/8”).
The end result is a baffle at the front of the can causing the airflow to slow down, split and partially tumble over the front baffle. The air is then forced to the bottom of the muffler via the center baffle and then forced upwards again via the rear baffle before exiting the dual tips.
I then welded the can with the new baffles on to the head and welded in a recessed end cap and drilled my dual exhaust outlet holes with a 2 ¼” hole saw. For added strength I welded a band around the circumference of the muffler at the spot where the can and ‘head’ went back together.
I purchased one set of stainless Corvette C6 exhaust tips off ebay for $25.
When they arrived I cut them at mirroring angles near the center split and ground them to the shape I needed for the right look. I then polished them (thanks again Dremel) and had my neighbor weld the tips on the muffler end cap for me since he has access to a stainless welder.
Since my driveway has fairly sharp transitions at each side causing a steep angle and the fact that my bike is a CG therefore lower than usual I’ve had a couple minor scrapes on the bottom of the muffler. To protect the underside of the muffler going forward I welded two 18 inch long, ¼ inch round hardened steel ‘runners’ just off the centerline of the muffler.
I then prepped and painted the muffler with 2000 degree flat black exhaust paint and reinstalled it.
Here’s the final look on the bike…
I’ve only ridden it about 60 miles since reinstalling but the sound is absolutely amazing with a nice low rumble and louder than stock without being TOO loud. I didn’t want it to sound like a Harley and there’s no chance it was going to sound like the typical I-4 sportbike, now it just sounds like… mine. I couldn’t be happier with the look as well; the dual Corvette tips are proportionately the absolute perfect tips.
Performance-wise it does feel a bit snappier through the entire band and so far I haven’t had the engine light come on. I suppose I’ll be purchasing a race ECM before long since that’s what I’ve read in countless posts regarding switching out mufflers but so far all is fantastic. There is occasionally very minor popping on decel but again it’s very minimal, nothing loud, and honestly it makes it sound a bit nastier which is sorta cool.
Comments welcome…
Thanks.
