MXA PRODUCT TEST: PRO DESIGN PRO-FLOW AIR FILTER KIT: Going Straight Is Better Than A Swerving Course

WHAT IS IT? A CNC-machined airbox ring that replaces the stock air box ring to allow air to have a straight shot at the intake tract.

WHAT’S IT COST? $179.95 (all models).

CONTACT? www.prodesignracing.com or (714) 534-0620.

WHAT’S IT DO? Decades ago, Pro Design found a way to get rid of the restrictive air filter cage, bracket and adaptor to clean up the inlet tract of a racing engine. The only problem? They built the kit for ATVs and quads, not motocross bikes. Since Pro Design owner Tom Burba has a solid motorcycle background that includes a long stint as a professional speedway racer and considerable Baja experience, it was only natural that he would eventually transfer his successful quad product over to motorcycles.

Burba’s original Pro-Flow filter kit has spawned many imitators, and Burba himself admits that his original design is just an extension of the old “green weenie” air filters of the 1970s. The concept is as simple and logical as can be: replacing the obstructions in the airbox (air filter cage, backfire screen and cage bracket) means your engine gets an added boost of unrestricted air.

WHAT STANDS OUT? Here’s a list of things that stand out with the Pro Design Pro-Flow air filter kit.

(1) Technology. The Pro Design Pro-Flow kit consists of a CNC-machined aluminum adapter plate (that replaces the stock plastic airbox intake plate), a two-stage foam air filter (that clamps onto the CNC-machined ring with a hose clamp), a wire mesh air filter cage (which is included in the kit, but not necessary) and a third-stage foam air filter cover (which can be removed after the first moto to reveal a clean filter for the second moto).

(2) Ease of use. Nothing could be easier. The air filter is held in place with a hose clamp that goes around the rubber lip of the airfilter to clamp it to the airbox ring. To remove the filter, all you have to do is loosen the hose clamp. There is no struggling with a bulky wing nut bolt.

(3) Performance. The unobstructed air intake guarantees that more air will flow into the engine. There is no cage, wire screen or cage mounting bracket to block the carb throat. On the dyno, the Pro Design Pro-Flow showed horsepower increases across the complete range (although not big gains), while on the track, every test rider said that the bike felt a little quicker in transition from mid-to-top.

(4) Installation. The Yamaha kit is a snap to install because Yamaha holds their airbox ring in place with a giant hose clamp. The Honda, Yamaha, KTM and Kawasaki kits require removing the bolts that hold the stock airbox ring in place.

(5) Air filter. The Pro Design Pro-Flow kit comes with a two-stage foam filter (and an extra foam air filter cover), but will also accept K&N pleated air filters or any clamp-on filter.

WHAT’S THE SQUAWK? Make sure that when you install the Pro-Flow kit you seal the ring in place with silicone seal.

You don’t have to be a genius to know that getting obstructions out of the intake tract is a positive step. This is a very good idea?-even if it did come from quads.