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i just recently did this to my bike. i bought a set of the tamper proof torx bits to remove the baffle screws. pulled out the baffles, took off all the fiberglass insulation, then drilled out 10 holes per baffle. i took a 1/4" bit and each time i drilled a hole, i would spin the baffle about 1/2" and move down about a 1/2" and drilled another hole. it worked really well for me.
When you pull the baffles in the 09-10 Street Bob mufflers, or the Fat Bob mufflers, this is what you've got:
As you can see, there is a thick steel mesh welded to the baffles that prevents you from getting to the actual baffle tube to drill those holes out. (This mesh is there to protect the fiberglass packing from the exhaust blast.) You're going to have to cut it off before you can enlarge the baffle holes.
If you want your exhaust to be just a tad louder than stock and a bit more throaty sounding, just remove the fiberglass packing and reinsert the baffles. I tried that and like the results very much. Don't go by how the exhaust sounds to you on the bike. Get someone to ride your bike and you stand on the side of the road and listen. You'll be pleasantly surprised.
Just realized the rivets are towards the inside of the bike so there is no way to drill them out while the pipes are still on the bike. I was trying to save myself a little time but I guess that wont happen.
Gary7: Thanks a lot for posting that picture. That helps me better understand what I am working with. What exactly has to be done after you remove the rivets to allow you to get to the fiberglass packing?
Did it multiple times before I bought aftermarket exhaust. Tried a few different things to improve the sound and performance. Lastly, just cut the stock baffle and welded in a straight pipe with a washer to provide some back pressure. Ultimately, it sounded better but nothing really improved the performance as much as the new pipes.
From: Back in the Good Ole USA. South Carolina to be exact.
Get a metal cutting hole saw and a drill extension. No need to take the rivets off unless you absolutely have to take out the packing.
I did this procedure w/the mufflers on the bike with a hole saw that fit the id of the outlet on the muffler. I don't remember the diameter, got it at Lowes. Just run it up in the baffle, holding it straight. It cut the plug out which amounted to little more than a metal disc effectivly giving me straight through glass pack mufflers. When the hole saw cut through, the plug was on the pilot drill of the hole saw.
Last edited by jluvs2ride; Aug 11, 2009 at 07:50 AM.
Get a metal cutting hole saw and a drill extension. No need to take the rivets of unless you absolutely have to take out the packing.
I did this procedure w/the mufflers on the bike with a hole saw that fit the id of the outlet on the muffler. I don't remember the diameter, got it at Lowes. Just run it up in the baffle, holding it straight. It cut the plug out which amounted to little more than a metal disc effectivly giving me straight through glass pack mufflers. When the hole saw cut through, the plug was on the pilot drill of the hole saw.
if you leave the pipes on, what do you do with the metal shavings? Turn the bike on and roll the throttle till they blow out?
i tried removing the baffles on my fatbob and drilling them out...i thought it sounded horrible...it sounded almost like something was loose or a weird rattle or something..and my buddies agreed..so i took out the baffles all together...i am thinking of going with a thunderheader at some point...but it does sound awesome with straight pipes...
"As you can see, there is a thick steel mesh welded to the baffles that prevents you from getting to the actual baffle tube to drill those holes out. (This mesh is there to protect the fiberglass packing from the exhaust blast.) You're going to have to cut it off before you can enlarge the baffle holes."
First off, thanks for a great picture of the baffle. I assume the fiberglass in question was wrapped around the mesh in several layers??
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