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Old 09-23-2013, 10:36 PM   #11
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I agree there is a point where more pleats do nothing and can start obstructing.

I would correct your statement and say "decreased restriction at the point that is the highest restriction in the path". Its not just the inlet, if I pinch a straw in the middle it does not matter how large the opening is at the end. the pinch is the point that is most restricting. On the motor's intake system I think its safe to say that the air filter is the most restrictive point. This is why going with a K&N drop in will result in "large" benefits with nothing else changed.

With the K&N you are reducing restriction by a different material that flows better. With a filter that provides a increased area such as more pleats it is providing more surface area. I think this would be the equivalent of have a physically larger filter with fewer pleats. This is of coarse limited in the scale that it can go.

This is my logic behind it.
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Old 09-23-2013, 10:58 PM   #12
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K&N drop in definitely better flowing material. Just remember that more pleats equals better filtration not increased flow(except when really dirty). If you use K&N drop in as an example. And say it has 50 pleats normally. If you just change the number of pleats in that filter from 50 to 25 you will have a gain in cfm but reduced surface area for filtration. If you go from 50 to 75 you will have a loss in cfm but a gain in surface area. But with 75 you have better filtration because of more surface area. Also if you take a standard K&N filter and cut it out to stretch it flat then that flattened filter will now have a much higher cfm.

Only talking about filters and flow dynamics based on physical size of filter, filter media used and numbers of pleats. Not talking about all the other restrictive aspects of intake systems or straws lol.

Just think of air as water in the terms of flow. They behave nearly identical when taking into account the increased friction coefficient of water.
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Old 10-01-2013, 10:12 AM   #13
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Huh. My logic was that a K&N was cleanable/reusable, so after four Fram filters (less than a year for me) the cost would even out. For high-mileage drivers like I am, that's important. And the slightly better fuel economy helps, too.
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