Washable and Reusable
A second and equally important attribute of a K&N filter is its ability to be cleaned. Simply wash, dry and re-oil the element at regularly scheduled intervals as illustrated in the cleaning instructions included with your Filtercharger (and in the back of this catalog), and it will continue providing your engine with clean air for the lifetime of your car. A K&N Filtercharger can be washed and cleaned up to 25 times. We recommend inspecting the filter every 30,000 miles or 12 months, especially when driving conditions for the year have been less than optimum.
Beyond the Stock Air Filter and Air Box
Addressing the next area of restriction, K&N engineers looked at the vehicle's air box (the container that houses the air filter) and any hoses or duct work connecting it to the engine. Because the air must first travel through this system before it reaches the carburetor or throttle body, the overall size and shape of the system has a profound effect on air flow. Because air flows like water, it does not like to turn corners nor does it react favorably when confronted by an obstruction such as a sharp bend in a hose or a baffle. In most cases, the air box and/or the hoses and duct work used to create the air filtration system is just as restrictive as the original paper filter element. In some extreme cases, the air box and/or the air delivery system is the greatest source of restriction. The inlet to the air box is a good example. In many instances this opening is one half the cross sectional area of the throttle body or carburetor opening. It would be like trying to run a marathon while breathing through a soda straw.
An original-equipment cylindrical air cleaner box covering a throttle body or carburetor is another example. Most often, these round air cleaner housings are sealed to the outside air. The engine must then breathe through a snorkel attached to the perimeter of the housing. At times the snorkel is fed through a network of hoses and scoops.
To directly address the problem, K&N have introduced a line of Filtercharger Injection Performance Kits (better know by the acronym, FIPK) that eliminates both the air box and the restriction. Our FIPKs vary in design because they are application specific meaning each kit is engineered to fit a particular make, model and year of vehicle.
FIPKs utilizes a 360-degree filter design which provides increased surface area to promote air flow. Port injected engines are outfitted with a conical shaped filter while centralized fuel injection systems are sized with an open element cleaner which again, makes available all of the air the engine can physically use.