Its been done, some who did it said they liked the result, otyhers, not so much, The Dyna weighs considerably less, is more attractive than any other Common muffler, tho I gotta hand it to Brave Teacher for puttin together a fine looking muffler, with that brass insert & all. His took some time, a Dyna is a grab & go kinda deal, except for havin a muffler shop build up an angled tube to join it to the header, I think some have managed to dodge that, but, wouldnt swear to it.,
My opinion? The stock exhaust is nothing short of hideous,.few others disagree.

I have no experience with the Dyna and that is the route I will eventually take more than likely.

I have an 07 s40 and def wanted a louder and deeper exhaust, I started by drilling 4 1/2 inch holes and it was louder and deeper but still pretty weak. I then moved to 4 3/8ths of an inch holes and it sounds 10 times better. Much louder and deeper sounds more like a motorcycle rather than a toy. It still isnt as loud or deep as I would like but for the price of free you cannot beat it. I have not rejet mine and I cannot notice any problems at all. I do still have the pops under decceleration though.

I would start with drilling 1/2 inch holes and see how you like it, then if you want more I would move up to 3/8ths.

Ended up w/ 5/16" hole size here. I like it. My bro's Dana sounds a little better, but it sure isn't any faster,....and both w/ stock jets, both on '07s
And after 4 yrs, his Dana still leaks at the muff inlet.
Its only fair to warn you (read dozens of posts here) that a Dana install is not straight forward,.....that most who have done it are still fighting leaks. So unless you are a real exhaust leak technition, or a good welder, think twice before ditching the stock exhaust. Myself, I like "original"

I'm not looking to make the sound louder, deeper, or more "cool," just to make the bike run better. Not clear, from people who have done it, that drilling out the baffles actually makes a noticeable difference in performance. Or does it?

In terms of adding the Dyna muffler, what kinds of performance improvements, if any, do you notice? I'd be particularly interested in acceleration improvements at highway speeds, as I don't feel as maneuverable as I'd like to there.

IMO, even If the Dyna offered zero change in sound & power, its a step up in look & ya lose a few pounds. But, ya do get a better sound, & it flows easier. YOu may or may not need a rejet,
If it was mine, Id get the OEM muffler off, just to make it easy on the muffler people & to make sure they didnt mess things up yanking/beating on the Trash Can, Ride it to the shop, let it cool off & show them what youre trying to do. Id definitely call ahead, make sure theyll do it for a reasonable price.

Waitaminnit,, Havent some people made the switch w/o having to have a bent part made? You spose theres some tiny swing in the header in or out that makes it work easier?

Anyway, If you can get some help & get the thing on w/o leaks, youll like the heck out of it I think,, Or, look at that thing Brave Teacher did, Thats a nice look, not a ton O $$, just add talent, skill & ability,,

Dont forget to take T-Clamps.
Id think a properly flared & slotted adapter with a good clamp would not leak, The adapter otta not run $20.00,, I dont think it should be more than $10.00, unless you get stainless, which would be nice, but it will go behind a shield. There are shields available that are straight, to replace that flared thing that goes to the Trash Can.

justin_o_guy2 wrote on 10/30/12 at 22:31:00:


Yeah it was late, I actually meant to say I started with 1/4 inch holes not 1/2.

Routy wrote on 10/31/12 at 06:45:22:


My experience as well. I had the Dyna but it leaked like heck. Supertrappp or the original is best in my opinion. I like the look of the Dyna but the super is cool too!!
This mine