Here’s a shot of the slip-on mufflers. Not too shabby, huh? Never heard of Akrapovic exhausts? The company has been manufacturing high-end performance exhausts for sport bikes and high-performance bikes for the past 20 years. It specializes in everything from MotoGP race motorcycle exhausts to exhausts for the Lamborghini Gallardo. It does all its manufacturing in its own factory, a factory comprised of everything from a foundry to pipe-making equipment, so every piece made is up to its standards. So now you know. Just about every Harley owner will end up modifying his or her exhaust to make it louder. As you all know, the stock exhaust makes the bike sound like a sewing machine. Sure it makes the old lady next door and the cops happy but when you are riding your Harley, you want to hear it  This contraption is the sound/flow control valve system. The Akrapovic touring slip-on with the optional valve system addresses both of those problems at one time. It is designed to give you a way to control noise and backpressure with one knob. Backpressure is something the Harley Twin Cam motor needs to run properly. Without it, low-end throttle response falls off and the bike feels sluggish at the low end. Yet with too much backpressure, the bike won’t run properly at higher rpm. Now, most aftermarket systems as of late address this very well. The optional valve set for the Akrapovic pipes takes it one step further and puts some extra control at your right hand. With one turn of the knob you can go from a basic amount of backpressure to a more wide-open system. Also it’s nice having a way to change the volume level and tone of your pipes with one knob. The install is pretty simple; check out how we did it. B  With the stock mufflers gone, we were ready to install the Akrapovic offerings.  As you can see, when the valve is open it can flow a ton of gasses straight through the muffler.  As you can see, when the valve is open it can flow a ton of gasses straight through th  With the butterfly closed, it offers as much backpressure as you could ever want.  The valve is slipped onto the stock exhaust with the new muffler going on right behind it.  The valve is slipped onto the stock exhaust with the new muffler going on right behind  The control knob was then taken out of its packaging and hooked up to the valve.  The knob itself was mounted above the starter right below the seat.  The heat shields were installed over the valve and we were done. We really like the organic look of the mufflers and dig the adjustments we can make on the fly.  The heat shields were installed over the valve and we were done. We really like the organic look of the mufflers and dig the adjustments we can make on the fly. Sources Akrapovic akrapovic.com Harley-Davidson Of Westminster hdwestminster.com By Chopper Dave Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!