I have stage two on my 09 Classic. Sounds cool and no decrease in performance. I have 6 holes, some have 4 some 8. I started with just punching the screen (Stage 1) ... not much difference. drilled 4 holes and sounded good. drilled two more and couldn't honestly tell any difference so stopped there as it sounds good. I had some popping on decel as noted on the forum but not severe. I did the marble mod and also unhooked the battery for 10 minutes, then hooked back up. This relearns the system and the popping is all but eliminated. Well, it seemed to work 4 me anyway. My one peice of advice is to start slow. Maybe stage one will satisfy you. If not, start with two holes, then four and so on. It's impossible to go back so be sure. This makes the bike sound like a motorcycle, not a sewing machine IMO.

 

Well. I just did a stage two on mine. Give me a couple days and I'll let you know. Hopefully some-one else can give you the answer sooner.

 

Well, I finally got to take the bike out for a good spin. I did not notince any loss of power to the bike. I drilled 4 5/16 inch holes in mine. I think most use a 3/8 inch hole. I just figured I would start with the 5/16. I can always go bigger if I want but I think I will leave it the way it is for now. I do like the sound allot better than the stock .

 

The front end of my mufflers are still there. I've cut the back off and wiggled the inner pipe loose. If'n you leave that front cap on you will have the required back pressure that will keep you from loosing low end torque. You won't pick up a bunch of HP increase and in fact I run the same settings on my 900 that I did on full stock setup without any leaning problems. There is a little power increase, when I put my backup set of full OEM pipes on I notice the loss, but it's nothing major.

 

I don't keep track of the "stages". By "stage 2", i think you mean drilling holes in the back of the muffler?

I've knocked the plug (screen) out and have four holes drilled into the back mine and i've experienced no decrease in power whatsoever. This is stricly seat-of-the-pants type reaction though, i've never put the bike on a dyno to prove anything.

 

I did stage 2 a year ago, screen punched and 4 holes drilled. I like the sound and will leave it at this stage.