BOYESEN POWER X-WING INTAKE TRACT
WHAT IS IT? Intake tract winglets have been around for decades. Do you remember Swirl-Up, Power Now, Dial-A-Jet, Tornado and Intake Twister? The Boyesen Power X-Wing is designed to increase power by improving airflow through the carb.
WHAT’S IT COST? $129.95—(800) 441-1177 or www.boyesen.com.
WHAT’S IT DO? Most people believe that an internal combustion engine is an explosive device—where fuel is lit off much like fireworks on the Fourth of July. Not true! Motorcycle engines are air pumps. Air is drawn in, compressed by force, expanded by combustion and expelled out the exhaust. Contrary to popular opinion, there is no explosion. The engine processes air, mixes it with fuel and burns the air/fuel mixture in a very orderly process. Once you understand how an internal combustion engine works, you can understand that the transition of air, from the airbox to the exhaust stinger, is all important. Nothing matters as much in the production of horse-power as the maximization, control and flow of air.
The Boyesen Power X-Wing works like an airplane wing. It takes a given volume of tumbled air and straightens it out. The goal is to achieve laminar flow. Laminar flow is the smooth, uninterrupted flow of air over the contour of a wing. The Power X-Wing reduces drag at the air’s boundary layer, reduces surface friction drag, equalizes the pressure gradient and increases air velocity.
That is a lot of techno-mumbo-jumbo, but what it means is that the Boyesen Power X-Wing is designed to increase air velocity--and, when air velocity increases, power increases.
WHAT STANDS OUT? Here's a list of things that stand out with the Boyesen Power X-Wing.
(1) Performance. In the saddle every test rider felt increased throttle response at low rpm, a smoother transition from the low-end to the midrange and a more flexible powerband across the range. Everything feels crisper and, best of all, the dips in the power curve are ironed out. The power is not only improved, but it becomes seamless from bottom to top. We tested the original Powerwing several years ago and liked it, but didn’t see any increase in power on the dyno. Not so with the new Power X-Wing (which is substantially larger and has an additional vertical airfoil that the original didn’t have). It gained one horsepower off the bottom up to 8000 rpm, but it is obvious that the big gain is in torque.
(2) Powerband. The increase in throttle response and improved transition paid its biggest dividends with Vet, Novice and Intermediate riders, because they spend more time working off the bottom.
(3) Mounting. The Boyesen Power X-Wing mounts inside the rubber air boot instead of inside the carb throat. The MXA wrecking crew liked this for three reasons: (a) It made installation as easy as pulling the air boot back and sticking the Power X-Wing in. (b) The clumsy unaerodynamic shape of the air boot is where the greatest improvement can be made in airflow. Trying to fix it at the carb throat is too little, too late. The X-Wing is located in the perfect place. (c) By putting the device in the air boot, the venturi size of the carb throat is not reduced by the thickness of the metal.
(4) Added test. Eyvind Boyesen believes in his products, and as the MXA gang was working with him on the Power X-Wing test on our YZ450F and RM-Z250, he mentioned that it worked even better on a Harley-Davidson. We called his bluff and put one in every Harley that the MXA gang has (2006 Street Glide, 1997 Sportster 883, 2005 Electra Glide FLHT and 1948 Panhead with an S&S carb), Shock! It worked. The jetting was improved, the idling smoothed out and power was improved noticeably.
WHAT'S THE SQUAWK? At $129.95, the aluminum wing-thing is expensive, but you aren’t buying the aluminum as much as the testing that goes into the shape of the wings.
RATING: FIVE STARS
We gave the original Boyesen Powerwing four stars because of the way it smoothed out the transitions and improved the throttle response. We like the Power X-Wing even more. Thus the five-star rating. As for our crackpot idea of testing them on our Harleys, we would give them six stars (if there were any such score).