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So I had the SE II slip-ons installed on my '06 Night Train with the SE breather and computer download. I liked the sound but found it somewhat strangled compared to the more throaty sound of a traditional Harley. My father works at the local dealership and we took a couple of slip-ons identical to mine off the shelf and examined them. What we found was a 'tab' (piece of the inner baffle bent downward toward the engine end of the exhaust) designed to deflect the exhaust up into the outer baffle corridor and then out the back of the exhaust. This 'tab' obstructs about 75% of the opening of the exhaust.

This has got to be what is strangling the sound of my bike.

It has been suggested to me that I can take a large dowel (or pipe) and insert it into the exhaust and tap it in order to slowly force the 'tab' upward and away from the exhaust opening in an effort to open the exhaust up and thereby tune the sound of the bike to my liking. It has been further suggested that I may be able to do this with the pipes mounted on the bike so long as I leave the end cap screw in (to hold the baffle in place) and I am careful while tapping. This would be much easier as it would allow me to fine tune the bike without having to uninstall and re-install the slip-ons with each slight adjustment.

Has anyone ever done this?

And more importantly, won't moving this tab out of the way affect the back pressure enough so that I may need to do another computer adjustment to accommodate the larger opening of the pipe (Harley Dealership seems to think not).

Thank you for your help.

Euth
 

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Use a cutting torch

A friend of mine tried everything to bend it and could not. He finally resorted to cutting it. It sounded so perfect- and ran so well- that I bought a set and we modified my baffles the same way. We cut about ¾ of the “tab” off in a parabola shape- leaving about a 10-15% obstruction instead of the original 75-80%. Sound is objective but it is a deep bass rumble. Can’t help you with the EFI question because I have a carb model. But it runs great- smooth pulling from idle to speed and I think I may have gained a couple of horses over the punched stock that I previously ran on my 05 Stage 1 DWG. If you are nervous about cutting, you may want to try it in stages.
 

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Pull out the baffle tubes (leave the fibreglass packing in place) and enlarge all of the 1/4" holes to 5/16". This will increase the area for the exhaust to get past from 1.4 sq. in. to 1.92 sq. in.
(assuming there are 24 holes). If you add an additional six 5/16" holes (for a total of 30) you will now have an area of 2.4 sq. in. which is the area of the
1 3/4 " exhaust pipe, so restriction is minimal. The tab is necessary to maintain the low end torque that goes away with straight through exhaust.
This modification will give a nice "neighborhood friendly" low frequency tone that will really "bark" when you roll on the throttle under load. I've tried several mods to my SEII's and found this one to give the best all around results. That's my contribution. Hope it helps. Longshadow
 

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Discussion Starter #4
longshadow said:
Pull out the baffle tubes (leave the fibreglass packing in place) and enlarge all of the 1/4" holes to 5/16". This will increase the area for the exhaust to get past from 1.4 sq. in. to 1.92 sq. in.
(assuming there are 24 holes). If you add an additional six 5/16" holes (for a total of 30) you will now have an area of 2.4 sq. in. which is the area of the
1 3/4 " exhaust pipe, so restriction is minimal. The tab is necessary to maintain the low end torque that goes away with straight through exhaust.
This modification will give a nice "neighborhood friendly" low frequency tone that will really "bark" when you roll on the throttle under load. I've tried several mods to my SEII's and found this one to give the best all around results. That's my contribution. Hope it helps. Longshadow
Dear God!

How many SEII's did you have to go through before you figured all of that out?
 

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Only one. Did the mods in steps until I got to where it is now. I started by bending the tab down and the results were disapointing. Sooo I reformed the tab to its original shape and position (had to use a torch to heat it) and started drilling out the holes a few at a time. First did every other hole in a row....tried it out..not there yet...drilled out the rest and added the extra holes, and that's where its at now. This was done over a period of a couple of months, riding a few hundred miles with each mod. I had previously tried the original SE mufflers (the type without the fibreglass packing...like cycle shack) but the sound was too raspy for my liking. (e-bay is a wonderful place to get low cost mufflers to try, and to sell when you are done with them).
Well, that's my story. Ride often, ride safe. Longshadow
 

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No loss of torque

There must be some difference between a carbed bike and an EFI re affect on torque. I experienced no noticeable loss of torque by cutting the baffle tab down to divert only about 10% of the flow. If anything, I gained a little over drilled out stock mufflers. But I admit that I am not trying to wring out a max peak via a dyno. All I wanted was good sound and good seat of the pants performance. Quite a few of the local club members have been impressed with the sound and quickness of the bike.

But mufflers are like beliefs- if we all had the same, life would not be as interesting. Good luck.
 
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