I converted my 950 Adv soon after I got it to single many years ago. Used an aftermarket pipe meant for an 1150GS so I know the flow was enough. Never could get the jetting just right and lived with a little less on the top end. (Bike would still do well over 110mph). Recently I decided the muffler needed a repack and pulled it of only to find my 2-1 had a rot problem at the hanger bracket. So I decided being that I had all the parts to put it back to 2-2 with Wings mufflers I would just go that way. Figured I'd have to mess with the jetting again but was shocked that it seems to be pretty much spot on. Pulls like a freight train. I even find myself shifting earlier than before. Just an observation about the 2-1.