is it true that you're generally going to get more torque and horsepower from a slip-on muffler versus getting dual pipes? if so, why is that? i know that dual free flowing exhaust might cost you some low-end torque, but thought you made up for it with the increase in HP in the higher RPMs and gears. the reason i ask is because of recent testing done on a dyno with a yamaha bolt and now a 950 which shows better results from a slip-on muffler versus duals. the first is a dyno chart of a V Star 950, and the second is from a Bolt.