Im not an expert on the theory. Just keep the can as close to 13" as you can. Shorter equals louder but dont expect the sound to double or anything, unless your gutting and chopping a stock can. My bike has no noticable difference other than louder since i chopped mine.

 

the sound is a concern, the pipe is loud already - not silly loud - but on the cusp of pissing my neighbours off, I set out for work about 6:30 am.

Would sticking in an extra baffle help or just make my life more complicated?

 

So you want a short muffler thats not loud?
Baffles only help so much. I say fook the neighbors And chop it.

 

If there is room you could put some of the baffle in the linkpipe with some sound absorbing fibreglass?

 

Cutting the can down will effect the tuning, most likely causing you to run a little lean, because of the increase in exhaust flow. You may need to jet depending on the performance after the cut.

 

I would cut as little off as I could and then try it out. If you want it shorter, then take the time to trim a little more off, etc. It is easier to remove a little at a time than it is to make it longer! I cut down a can for my current SV and when I had it all apart I stuck an awl in the perforated tubing and bent about 100+ of the holes inward by levering on the awl. So now there are a lot of little fins that hang down to grab the exhaust flowing through. It did cut the noise down some.

 

or.... if its too loud after you cut it down, you could do whats known as the "lollipop mod" wich would let you tune the db and back pressure

 

Hmm, that's a pretty ingenious little mod there.

 

I believe that the tightness of the wrap around the baffle has a little effect on the sound output. Shortening it will surely make it louder but depending on how much you shorten it. If you cut it in half it would probably be a good deal louder. Definately wont make it any quieter :metal: supertrapps are good for reducing sound but whether you want a cap on your exhaust or not.

 

Lolipop mod will not quite the noise... It will however, archaically adjust backpressure...

What sucks here is that you'll never get it running to it's full potential until your set in stone with the can/ backpressure... Then jet/tune... then leave it alone...