Attention: TDR Forum Junkies Cruzin the web I ran onto this and found it interesting. Its a response to a K&N basher from someone who works for them. Its rather long but seem to make sense to me. I found it here, http://www.rv.net/forums/index.cfm/fuseaction/thread/CFB/1/Tid/151191/DoOnePage/Yes.cfm
"Kenneth here's the K&N response to the site you posted.
Dear customer,
That is basically made up information. It is not scientific nor is it
quantified. How the heck can his test data show a 1. 1% difference in
filtration and that be a 224% increase? 99. 2 - 98. 1 = 1. 1 in my world, not
224. Our filters are tested by an outside, independent laboratory. They
have been proven to stop at least 99% of particles on a SAE dust test. This
test uses particles as low as the 0 - 5 micron range and goes up to 20
microns. For comparison, a paper filter also stops 99% on the same test and
the OEM minimum standard is 96%. Foam is generally the worst media with a
typical efficiency rating of 75 - 85%. To get higher ratings, the foam must
be more dense and therefore way more restrictive. The "tack" characteristic
of a K&N allows for increase filtration without loss of flow as well.
The testing procedure used is SAE J-726 using ISO Test Dust. This test
is the standard of the air filter industry. The test procedure consists of
flowing air through the filter at a constant rate (airflow rate is
determined by the application) while feeding test dust into the air stream
at a rate of 1 gram per cubic meter of air.
As the filter loads with dust the pressure drop across the filter is
increased to maintain the prescribed airflow rate. The test is continued
until the pressure drop increases 10" H2O above the initial restriction of
the clean element (in this case . 78" to 10. 78" H2O). At this point the test
is terminated. The dirty filter element is then weighed. This weight is
compared to the clean element weight to determine the total Dust Capacity.
The amount of dust retained by the filter is divided by the total amount of
dust fed during the test to determine the Cumulative Efficiency.
The K&N filter achieved the following results:
Dust Capacity: 305 grams
K&N Cumulative Efficiency: 99. 05 %
Holding the filter to the light is useless, pin holes are normal. That
is what makes a K&N filter. There are actually hundreds of microscopic
fibers that cross these holes and when treated with oil, capture and hold
the very fine particles. On the same hand, they allow the filter to flow
more air than paper or foam. The filter is 4 ply cotton gauze unlike some
competitors synthetic material filters. The synthetics do not have the very
small fibers that natural cotton does. Also, the oil can be pulled off of a
foam filter contaminating electronic sensors. It will absorb into cotton
and stay in the media.
We got started over 33 years ago making filters for motorcycles and off
road racers. The filters did so well that these guys wanted them for their
cars and trucks. We started making filters for these applications and here
we are today. If they did not work, we would not still be here and growing
every year.
We now make filters for Chrysler/Mopar, Ford Motorsports, Edelbrock,
Rotax Engines, and Harley Davidson. We come as original equipment on the
2000 Ford Mustang Cobra-R. We even made filters for the Apache helicopters
used in Desert Storm because of maintenance problems with the original paper
design. If they work in these conditions they will work for you. Links to
the filtration tests are on our web site at
http://www.knfilters.com/images/factstab1.gif and
http://www.knfilters.com/images/factstab2.gif Here are pictures a customer
with a Ford sent us on how well the filter does on his truck...
http://www.nx2k.com/truck/kn_filter_dirty_or_not.htm Bottom line, chat
rooms are not always the best places to get sound information. 33 years of
making filters vs. arm chair engineers such as Sean or some guy called the
"land shark"? What do you believe?
Thanks for writing, Rick"
"Kenneth here's the K&N response to the site you posted.
Dear customer,
That is basically made up information. It is not scientific nor is it
quantified. How the heck can his test data show a 1. 1% difference in
filtration and that be a 224% increase? 99. 2 - 98. 1 = 1. 1 in my world, not
224. Our filters are tested by an outside, independent laboratory. They
have been proven to stop at least 99% of particles on a SAE dust test. This
test uses particles as low as the 0 - 5 micron range and goes up to 20
microns. For comparison, a paper filter also stops 99% on the same test and
the OEM minimum standard is 96%. Foam is generally the worst media with a
typical efficiency rating of 75 - 85%. To get higher ratings, the foam must
be more dense and therefore way more restrictive. The "tack" characteristic
of a K&N allows for increase filtration without loss of flow as well.
The testing procedure used is SAE J-726 using ISO Test Dust. This test
is the standard of the air filter industry. The test procedure consists of
flowing air through the filter at a constant rate (airflow rate is
determined by the application) while feeding test dust into the air stream
at a rate of 1 gram per cubic meter of air.
As the filter loads with dust the pressure drop across the filter is
increased to maintain the prescribed airflow rate. The test is continued
until the pressure drop increases 10" H2O above the initial restriction of
the clean element (in this case . 78" to 10. 78" H2O). At this point the test
is terminated. The dirty filter element is then weighed. This weight is
compared to the clean element weight to determine the total Dust Capacity.
The amount of dust retained by the filter is divided by the total amount of
dust fed during the test to determine the Cumulative Efficiency.
The K&N filter achieved the following results:
Dust Capacity: 305 grams
K&N Cumulative Efficiency: 99. 05 %
Holding the filter to the light is useless, pin holes are normal. That
is what makes a K&N filter. There are actually hundreds of microscopic
fibers that cross these holes and when treated with oil, capture and hold
the very fine particles. On the same hand, they allow the filter to flow
more air than paper or foam. The filter is 4 ply cotton gauze unlike some
competitors synthetic material filters. The synthetics do not have the very
small fibers that natural cotton does. Also, the oil can be pulled off of a
foam filter contaminating electronic sensors. It will absorb into cotton
and stay in the media.
We got started over 33 years ago making filters for motorcycles and off
road racers. The filters did so well that these guys wanted them for their
cars and trucks. We started making filters for these applications and here
we are today. If they did not work, we would not still be here and growing
every year.
We now make filters for Chrysler/Mopar, Ford Motorsports, Edelbrock,
Rotax Engines, and Harley Davidson. We come as original equipment on the
2000 Ford Mustang Cobra-R. We even made filters for the Apache helicopters
used in Desert Storm because of maintenance problems with the original paper
design. If they work in these conditions they will work for you. Links to
the filtration tests are on our web site at
http://www.knfilters.com/images/factstab1.gif and
http://www.knfilters.com/images/factstab2.gif Here are pictures a customer
with a Ford sent us on how well the filter does on his truck...
http://www.nx2k.com/truck/kn_filter_dirty_or_not.htm Bottom line, chat
rooms are not always the best places to get sound information. 33 years of
making filters vs. arm chair engineers such as Sean or some guy called the
"land shark"? What do you believe?
Thanks for writing, Rick"
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