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The paper filter has 5 1/2 times the surface area, must be some big ass holes (do not want) in a k&n to flow more.
Huh? Suck a Given CFM of air through 1 square foot of filter media, and suck the same CFM through 5 square feet of filter media, which one is going to be more restrictive?
I see what you are saying CFM's are CFM's and if you are sucking the same amount of CFM's through each filter media then the restriction will be the same. I still think K&N makes a bold claim and they have a lot of information on their website that really takes a look at the basic principles of air filtration. The below article is right from their website I know most of you will say that of course they are going to tell you cotton (K&N) is better because they are trying to sell it to you, but the information is thought provoking nonetheless.
I see what you are saying CFM's are CFM's and if you are sucking the same amount of CFM's through each filter media then the restriction will be the same. I still think K&N makes a bold claim and they have a lot of information on their website that really takes a look at the basic principles of air filtration. The below article is right from their website I know most of you will say that of course they are going to tell you cotton (K&N) is better because they are trying to sell it to you, but the information is thought provoking nonetheless.
Filtration 101 - A Deeper Cut
Most people believe that all air filters function on a go/no go basis where dirt particles that are larger than the openings in the filter media are trapped while particles that are smaller than the openings can pass right through. A dry paper air filter does function in this manner. That’s why paper filters are so restrictive to air flow. The openings in this type of filter have to be very small to filter efficiently.
The oiled cotton media used in the K&N air filter functions in an entirely different manner. There are scientific principles that determine how an air filter removes dirt particles from the air stream. The first of these principles is known as interception, which applies to dirt particles traveling with the air stream. Air flow will always take the shortest path and as the air is forced to flow around the filter’s fibers some of the particles will contact the sides of the fibers and be captured. These particles are then held in place by the oil or tacking agent in the fiber.
Another principle is known as impaction, which mostly affects larger or heavier dirt particles. Impaction occurs when the inertia or momentum of the particle causes it to deviate from the flow path. In other words the heavy particles do not follow the air stream around the filter’s fibers but instead they run straight into the fibers and are captured.
The most important principle for our use is diffusion, which deals with the laws of physics that govern the motion of very small dirt particles. Small particles are highly affected by the forces in the air stream. Forces such as velocity changes, pressure changes, turbulence caused by other particles and interaction with the air molecules cause these very small particles to become random and chaotic. As a result, these particles do not follow the air stream and their erratic motion causes them to collide with the filter’s fibers. This phenomenon enables an air filter to capture dirt particles that are much smaller than the openings in the media. In addition, the way that dirt collects or loads on the K&N filter is very different. A paper filter exhibits "surface loading" which means dust collects only on the surface of the media. In contrast, K&N filters exhibit "depth loading". The multiple layers of cotton fibers provide many levels of dust retention. This characteristic allows the K&N filter to hold significantly more dirt per square inch of media than the average paper filter. Utilizing these scientific principles, K&N has been able to design an air filter that is very free flowing while also being highly efficient at removing dirt from the air.
They have more info on things like Paper vs. Cotton (K&N) if you want to look at it http://www.knfilters.com/filter_facts.htm. I may have just added more fuel to the fire by bringing this up, but they claim their filters will flow more. I know most people are using the "seat of the pants" dyno to say they don't make any more noticeable power, but the flow bench tests show they do. K&N filters are most appealing to me mainly because they are a one time purchase (Have the same one in my Dad's 99 Power Stroke since 99) and if oiled and cleaned correctly they make for a good investment IMO. Not looking to start any feuds I am just giving my opinion and some correlating information.
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