K&N made their name in the dirty filter area.  They can get soaked in water, like when you dump your dirtbike in the creek, and will clear up after you clear the cylinders of water.  The competition was oil-soaked foam though, not paper.

There used to be ads out there showing how the dirt would build up on the oil soaked outer surface creating more and better filtration.  Supposedly the dirt would drop off as it the buildup got too heavy, like some sort of self-sustaining media.  I remember being fascinated by the concept of more dirt resulting in a cleaner air supply.  Looking back, it was all marketing BS.  I copied a segment from K&N's web site that should immediately trigger anybody's BS sensor.  Setting the stage, mentally, for flow is more important than clean if you want to "win the race".

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

http://www.knfilters.com/filter_facts.htm

Edited December 28, 20168 yr by Zed Head

Check out the filter for the filter.  FLOW is important.  Until they have something else to sell you.  Then, not so much.

http://www.knfilters.com/news/news.aspx?id=5690

And, just ignore test results if you mean well.  It's a top priority, whether it's achieved or not.  K&N is a marketing company.

Of course, efficiency is undefined so it could mean flow.  Plausible deniability.

 

Edited December 28, 20168 yr by Zed Head

That's a lot of K&N bashing above, but those nice-looking foam pieces that people use on their ITB's or carburetors are probably worse.  Just know the tradeoffs is the message.  K&N's are dirty filters.

4 hours ago, psdenno said:

The topic does make for good discussion over a couple beers.  But, like politics and religion, minds probably won't be changed as a result.  I will now step off my soap box and slide it back under my desk until next time 

No not at all, real results like yours count a lot more than say Mythbusters.  My opinion of K&N comes from one of their filters I put on a ford 302 that I had installed in a Triumph TR6. I drove the car for the whole season, maybe 4-5000 miles and when I put the car away for the winter I removed the filter and ran my finger around the air horn going down into the four barrel, my finger came up covered in oily grit, fine sand and it was evenly deposited so it wasn't a leak or perforation. That's when I threw the K&N in the garbage and went back to paper.

When an air filter catches a particle, that particle restricts air flow at it's location, so the incoming air takes the path of least resistance, a clean area of the filter. When the filter is very dirty, there's no clean area, so incoming air is sucked through dirty areas, bringing dirt into the engine with it. That will happen with paper or K&N.

My friend had a Nissan SUV that was dying on the freeway. Stock filter had probably never been replaced. Filter was packed with dirt and lots of dirt had made it past the filter and collected in lower part of the filter housing. I guess a lot also got sucked into the engine. We shook the filter until about half a coffee can of dirt fell out. Guess cars on the freeway kick up a lot of dirt.

So maybe if it's a paper filter change it frequently; if K&N clean frequently. I got those pre-filters for my round K&N's, might keep them clean a little longer.

12 minutes ago, Stanley said:

So maybe if it's a paper filter change it frequently; if K&N clean frequently. I got those pre-filters for my round K&N's, might keep them clean a little longer.

Perfect advice.  Whether it's a car's air filter or oil filter, or the filter in your home HVAC, as soon as they start to do their job their efficiency begins to decline until, ultimately, they are no longer effective.   Timely filter changes is the way to go no matter what kind you use.

Dennis

12 minutes ago, Stanley said:

 

 

how do i clean the filter when its get dirty? Just water or do i need to buy the cleaning kit!

Buy the cleaning kit

Actually, what you need to buy is a Recharge Kit.  It contains a cleaning fluid that removes the old oil from the cotton filter material and also contains a spray can of new oil to apply to the filter after cleaning and before reinstalling on the car.  Kits are inexpensive and last a long time.  Available from K&N or any vendor that sells the filters.

Dennis