(2.)We started by pulling off the stock Harley-Davidson air cleaner cover.
(3.)The OEM Air filter element and backing plate were both removed.
(4.)With all the parts removed we cleaned and checked the throttle body for any debris.
(5.)The first step to installing the Aircharger was to mount the breather line to the cylinder heads with the supplied hardware.
(6.)We installed the rubber breather tube that mounted to the rear of the K&N; throttle body backing plate.
(7.)The "elbow" throttle body plate was bolted into place with plenty of blue thread locking compound.
(8.)K&N;'s patented high-flow air filter was bolted to the throttle body plate and the stainless steel filter clamp was tightened.
(9.)As you can see the look of the Aircharger is right at home on our '09 Street Glide and actually classes it up a bit, not to mention adding 10+ horses.
(10.)The Dyno Graph showed that our bike had a baseline of 66.37hp and when fitted with the Aircharger the horsepower increased to 76.79hp.
We were lucky enough to be invited for a sneak peek of K&N; Engineering's new Aircharger elbow-style intake at its Southern California facility. K&N; also let us bring along our project FLHX for a little dyno testing to see what performance gains, if any, could be had with the Aircharger.
Switching to an elbow-type intake is not only for added looks, but the design aids in making more horsepower in two ways. The first is by having the intake situated away from the bike's warm cylinder heads it can get cooler air into the engine. The engine likes cold air because cooler air has a higher density and greater mass per unit volume. This means that cold air has more oxygen to burn during the combustion process than heated air does. The second reason is that most elbow intakes have a greater intake surface due to the "cone" design of the air cleaner so it just plain sucks in more air than a standard design.
Knowing all of these things, we were still surprised when the K&N; Aircharger alone on our stock '09 FLHX garnered a 10.42hp increase no doubt due to it's throttle body plate design and patented air cleaner materials.
The Aircharger is an easy to install kit that anyone with a few common handtools can conquer well inside an hour. It's simple, yet elegant design looks good and makes horsepower.
Aircharger Intake $349