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I have recently had a run of these particular surgeries across several models and realised it was an opportunity to document the process for anyone who may be interested. WARNING: Some images may be disturbing to Tiger lovers! (No Meerkats were harmed in relation to this procedure.)
 

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Not many people get to see the internals of their mufflers, so here are some photos of the baffling which the exhaust gases need to navigate their way through. In each of the models the same muffler philosophy was used.

I left the catalytic converter in each of these systems. The object of the exercise was more breathing and more growl, and I found that keeping the cat box in place maintains good header pressure and generally doesn't require re-tuning for the average rider.

The third photo shows the size of the original outlet compared with the first baffle the exhaust needs to negotiate. As you can see, the final outlet size is not reflective of what's behind it and has no relationship to the overall gas flow. It is mostly cosmetic.

This is purely a shapshot - if anybody is serious about doing this and wants more detail, just contact me.
 

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That’s interesting. How is the sound compared to after market mufflers. I got a Yoshimura with my used Tiger, but previous owner had put the stock muffler back on it. He said the Yosh was too loud. I’m just about to agree with him. Got some pretty annoying droning lately with the Yosh. In the original Concours world, bafflectomy means shoving a one inch hole saw down the muffler and drilling away. I did not do that to my Concours.
 

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That’s interesting. How is the sound compared to after market mufflers. I got a Yoshimura with my used Tiger, but previous owner had put the stock muffler back on it. He said the Yosh was too loud. I’m just about to agree with him. Got some pretty annoying droning lately with the Yosh. In the original Concours world, bafflectomy means shoving a one inch hole saw down the muffler and drilling away. I did not do that to my Concours.
Not loud 93/94db soft and solid no, tin can tang.. or bark.
For me bafflectomy is do whatever is necessary to achieve best sound possible. with little or no external evidence.
you may get rid of the drone by increasing the internal muffler pressure, by reducing the outlet diameter one or two pipe sizes and make the muffler packing work harder and capture the reverse pulse in the muffler rather than two inches beyond the outlet .
cup your hand at the exhaust outlet and move your hand in and out a few inches from the end see if there is a blat!!!!
or put your hand across the muffler outlet to block off one third of the opening to see if the sound firms up .
very hard to relate this type of information in the written word .
cheers
 

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Hello, find this publication and if you could advise me, I would appreciate it, before I had a Yamaha SCR950 and only perforated the bottom of the baffle to increase the sound, (it is a common modification on that motorcycle), now, seeing the photos in this post I see that the bottom of this baffle (the metal foil with a stamped X) only divides the inlet and the outlet, so if I pierce it with a saw it should pass the gas straight out without going through the baffle, is this correct? If so, what kind of sound can I expect? and what difference in torque can i expect? again I appreciate any information, and send you a greeting from Mexico.
 

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Yes, if you break through that plate the gas will have direct access .With the size hole that could be made accessing through the inlet or outlet the difference would be minimal . if it was that easy,that's what I would have done.
 

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MMM, I wouldn't expect a torque spike by reducing the OEM back pressure. This exhaust is "tuned" to this engine's gas flow characteristics. Without going into "fluid dynamics," let's just say you'd lose power in the middle RPM range, where we spend the majority of our riding time.
 

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The modern exhaust is a compromise between regulation and performance.
With the hundreds of exhausts I have modified both opening up and restricting ,I have found best results are when the outlet is within one pipe size of the header pipe .
Across the spectrum of makes and models the most noticeable change is throttle response. There is the placebo effect of more sound ,but this doesn't explain reducing the sound and increasing the back preasure and getting more response.
Torque gains recorded on a dyno are less important to me than rider pleasure.
I get a lot of smiles...
Peter H
 

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I switched out the TOR for the standard can because of the drone on long rides, but I do miss the sound on shorter blasts around town. Has anyone figured how to tune the sound on the fly?
 

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The modern exhaust is a compromise between regulation and performance.
With the hundreds of exhausts I have modified both opening up and restricting ,I have found best results are when the outlet is within one pipe size of the header pipe .
Across the spectrum of makes and models the most noticeable change is throttle response. There is the placebo effect of more sound ,but this doesn't explain reducing the sound and increasing the back preasure and getting more response.
Torque gains recorded on a dyno are less important to me than rider pleasure.
I get a lot of smiles...
Peter H
My new Tiger 900 should be in the shipment Sept-Nov. I plan on asking Peter at Meerkat to work his magic on the standard exhaust for the outcomes he's mentioned above. If no-one gets in first, I might be the guinea pig?

Not many people get to see the internals of their mufflers, so here are some photos of the baffling which the exhaust gases need to navigate their way through. In each of the models the same muffler philosophy was used.

I left the catalytic converter in each of these systems. The object of the exercise was more breathing and more growl, and I found that keeping the cat box in place maintains good header pressure and generally doesn't require re-tuning for the average rider.

The third photo shows the size of the original outlet compared with the first baffle the exhaust needs to negotiate. As you can see, the final outlet size is not reflective of what's behind it and has no relationship to the overall gas flow. It is mostly cosmetic.

This is purely a shapshot - if anybody is serious about doing this and wants more detail, just contact me.
Not loud 93/94db soft and solid no, tin can tang.. or bark.
For me bafflectomy is do whatever is necessary to achieve best sound possible. with little or no external evidence.
you may get rid of the drone by increasing the internal muffler pressure, by reducing the outlet diameter one or two pipe sizes and make the muffler packing work harder and capture the reverse pulse in the muffler rather than two inches beyond the outlet .
cup your hand at the exhaust outlet and move your hand in and out a few inches from the end see if there is a blat!!!!
or put your hand across the muffler outlet to block off one third of the opening to see if the sound firms up .
very hard to relate this type of information in the written word .
cheers
 
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