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Anyone drill their stock exhaust ?


dony

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I wonder if drilling the actual pipe that comes from the converter or chopping off all together changed the sound much while still allowing proper emissions.
It's been done before. The guys who tried drilling inside the pipe ended up drilling the 6 - 3/8" holes anyway because it made little difference. Chopping off altogether? Like straight piping it?? 
There's no need to wonder if straight piping it would change the sound or allowed proper emissions. lol

Not chopping the cat off. Just the bit of pipe that extends from the back of it
 
EDIT: on further digging I've found my answer. I new have an idea I plan to try tomorrow.
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It's been done before. The guys who tried drilling inside the pipe ended up drilling the 6 - 3/8" holes anyway because it made little difference. Chopping off altogether? Like straight piping it?? 
There's no need to wonder if straight piping it would change the sound or allowed proper emissions. lol

Not chopping the cat off. Just the bit of pipe that extends from the back of it 
EDIT: on further digging I've found my answer. I new have an idea I plan to try tomorrow.
Not sure that would do anything, the exhaust gases are for the most part bypassing that pipe with the holes drilled. I believe it's just there to function as an exit point with the stock exhaust cover. 

2016 FZ07 - LOVING IT!!
2003 R6 - SOLD
2006 FZ6 - SOLD

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I remember when I was younger having holes in your exhaust was a sign of poverty. guess it really has not changed that much.
 
just so you all know if you ever run into an office of the law who knows a thing or two these little holes could be a problem
 
TAMPERING PROHIBITION
Federal law prohibits any modification to this exhaust system which causes the motorcycle to exceed the Federal
noise standard. Use of the motorcycle with such a modified exhaust system is also prohibited.
Acts likely to constitute tampering include removal or puncturing the muffler, baffles, header pipes, or any other
component which conducts exhaust gases.

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I remember when I was younger having holes in your exhaust was a sign of poverty. guess it really has not changed that much.  
just so you all know if you ever run into an office of the law who knows a thing or two these little holes could be a problem
 
TAMPERING PROHIBITION
Federal law prohibits any modification to this exhaust system which causes the motorcycle to exceed the Federal
noise standard. Use of the motorcycle with such a modified exhaust system is also prohibited.
Acts likely to constitute tampering include removal or puncturing the muffler, baffles, header pipes, or any other
component which conducts exhaust gases.
Solution: internal modification instead of exterior. Unless a meter is taken to it you'd be safe.
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  • 5 weeks later...

Hi everyone,
 
I drilled my exhaust and it sounds much much sweeter now, I have three 3/8th holes on the top and two 1/4th at the bottom of the chamber around the tail pipe. Could anyone one of you let me know if you are experiencing a leaner fuel mixture on their bikes, at least on the mpg calculator? I should not typically experience any changes in fuel mixture based on all your experiences, but my mpg counter just went through the roof. It's reading an average of 90+.
 
Thanks for your advice!

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I did it this week actually. Being a two cylinder, I can kinda rationalize the sound of every individual hit of the cylinders in their combustion strokes. Personally, I love it. I drilled 6 3/16" (3 above the exit pipe and 3 below, after taking the shroud off). I haven't noticed any issues with power, performance, or fuel economy. Drilled right, you don't even see the holes once the shroud is back on. I'll need to keep an eye on it to make sure it doesn't rust inside or anything. The original idea called for 1/4" holes drilled. I might do that after a few weeks

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  • 3 weeks later...
I did it this week actually. Being a two cylinder, I can kinda rationalize the sound of every individual hit of the cylinders in their combustion strokes. Personally, I love it. I drilled 6 3/16" (3 above the exit pipe and 3 below, after taking the shroud off). I haven't noticed any issues with power, performance, or fuel economy. Drilled right, you don't even see the holes once the shroud is back on. I'll need to keep an eye on it to make sure it doesn't rust inside or anything. The original idea called for 1/4" holes drilled. I might do that after a few weeks
 Hey! 
Could you please let me know if you were able to go up to 1/4" inch holes? If so how many and were you able to notice a good sound difference?
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I did three 3/8" holes on top and two 7/16" holes on bottom.  Happy with the sound, no issues with performance or fuel consumption; (although with the money I saved not buying an aftermarket exhaust and fuel controller I can buy a few hundred gallons of gas anyway!)

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  • 1 month later...
I did it this week actually. Being a two cylinder, I can kinda rationalize the sound of every individual hit of the cylinders in their combustion strokes. Personally, I love it. I drilled 6 3/16" (3 above the exit pipe and 3 below, after taking the shroud off). I haven't noticed any issues with power, performance, or fuel economy. Drilled right, you don't even see the holes once the shroud is back on. I'll need to keep an eye on it to make sure it doesn't rust inside or anything. The original idea called for 1/4" holes drilled. I might do that after a few weeks
 Hey! 
Could you please let me know if you were able to go up to 1/4" inch holes? If so how many and were you able to notice a good sound difference?
 
Sorry for the late reply, I never looked at my notifications, sorry! Yea, I've been thinking about doing it very soon, maybe tomorrow. I'll let you know how that sounds then
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I would drill 3 3/8" holes in the bellypan exhaust like the 3 red circles here:
Should make it more noticeably loud, while not being too overly loud, and exit any liquids that may have gotten in there if drilled on the bottom.
Also the heat shield will keep up better, and not get full of carbon over time on the inside.
 
On second thought, perhaps not a center one, because you don't want to blow hot exhaust on the rear tire.
So just the 2 outer holes, just for noise purposes.
On my 50cc scooter, I drilled 2 x 3/8" holes, and it sounded pretty ok.
I don't think 2 will make a huge volume increase, mainly at idle, or low rpm.
The more you'll add, the louder it'll become, and relatively louder at higher RPM than at idle.
 
1.jpg
 
image upload
 

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I drilled directly into my pipe going straight down. Went theough the pipe and one silencer wall. Looking in you can see the catalytic converter.
 
Following this method you still get better sound while maintaining the same exit point for the exhaust gas.
 
 

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I drilled directly into my pipe going straight down. Went theough the pipe and one silencer wall. Looking in you can see the catalytic converter.  
Following this method you still get better sound while maintaining the same exit point for the exhaust gas.
 
 
But you'll need a seriously long drill, and not everyone has that (plus the chance on the drill bit falling out, or breaking off, into the chamber...)
 

 
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I drilled directly into my pipe going straight down. Went theough the pipe and one silencer wall. Looking in you can see the catalytic converter.  
Following this method you still get better sound while maintaining the same exit point for the exhaust gas.
 
 
But you'll need a seriously long drill, and not everyone has that (plus the chance on the drill bit falling out, or breaking off, into the chamber...)
 

Not at all. A 8$ extention and a hole saw rated for metal is all you need. And considering they're made for this application it is hard to see them failing.
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