Delkevic and Danmoto offer a full system exhaust for this bike. I've looked at the Delkevic dyno and it adds...1 hp.
The page did not mention anything about weight reduction. I'd assume switching from two to one muffler would reduce the weight a decent amount. Anyone do this mod and notice any significant benefits? The nature of the N1K was drastically changed when I did a full system. Dropped the weight 25 lbs and makes it way more maneuverable, and working on it is easier because the left muffler isn't in the way.