I do some dyno test at work and on most cars there are
no power gain by using a K&N air filter to replace the paper
filter. For example, a turbocharged 4 cylinder engine got a
3 Nm increase at 3000 rpm (that's 2 lb-ft) but nothing at the
top end. More important is how the air get to the filter housing
as by replacing the factory air box with the popular cone type
air filter actually reduced top end power with 4 hp because it
had to suck the hot air next to the engine. I admit using K&N
air filters myself as I live in a part of the world where there
isnt much dust in the air, but I dont expect any power gains
from the filter itself.
0.02
Thomas
John F Sandhoff wrote:
> This last showed up on the Roadster list in August 1997, posted then by
> Barrie Strachan. It apparently came from the Mazda list, which came
> from the Volvo list, which came from an automotive BBS somewhere.
> I make no claims pro or con for K&N - I'm just passing this along..
>
> -- John
> John F Sandhoff sandhoff@csus.edu Sacramento, CA
>
> > Subj: K & N filters
> > To: John M. Saturday, January 21, 1995 5:14:10 PM
> > From: George Morrison
> >
> > John: If I wrote "subjective" I meant "objective".. I was
> > responsible for evaluating re-usable air filters
> > for a major construction/mining company that had
> > hundreds of vehicles ranging from large earthmovers
> > to pick-up trucks and salesmen's cars. This study
> > was embarked upon due to the fact that we were
> > spending upwards of $30,000 a MONTH on paper air
> > filters. Using them one time then throwing them
> > away.. I inititated the study in that I was convinced
> > that a K&N type filter or oiled foam would save us
> > many dollars per year in filter savings, man hour savings,
> > and of course engines as these would filter
> > dirt better than paper. (yes, I had read the K&N ads and was
> > a believer)
> >
> > Representative test units were chosen to give us a
> > broad spectrum from cars right through large front
> > end loaders. With each unit we had a long history
> > of oil analysis records so that changes would be
> > trackable.
> >
> > Unfortunately, for me, every single unit having
> > alternative re-usable air cleaners showed an immediate
> > large jump in silicon (dirt) levels with corresponding
> > major increases in wear metals. In one extreme
> > case, a unit with a primary and secondary air cleaner,
> > the secondary (small paper element) clogged
> > before even one day's test run could be completed.
> > This particular unit had a Cummins V-12 engine
> > that had paper/paper one one bank and K&N/paper on
> > the other bank; two completely independent
> > induction systems. The conditions were EXACTLY
> > duplicated for each bank yet the K&N allowed so
> > much dirt to pass through that the small filter became
> > clogged before lunch. The same outcome occured
> > with oiled foams on this unit.
> >
> > We discontinued the tests on the large pieces almost
> > immediately but continued with service trucks,
> > formen's vehicles, and my own company car. Analysis
> > results continued showing markedly increased
> > wear rates for all the vehicles, mine included.
> > Test concluded, switched back to paper/glass and all
> > vehicles showed reduction back to near original levels
> > of both wear metals and dirt. I continued with
> > the K&N on my company car out of stubborness and at
> > 85,000 miles the Chevy 305 V-8 wheezed its
> > last breath. The top end was sanded badly; bottom
> > end was just fine. End of test.
> >
> > I must stress that EVERYONE involved in this test
> > was hoping that alternative filters would work as
> > everyone was sick about pulling out a perfectly good
> > $85 air cleaner and throwing 4 of them away
> > each week per machine...
> >
> > So, I strongly suggest that depending upon an
> > individual's long term plan for their vehicles they simply
> > run an oil analysis at least once to see that the
> > K&N or whatever alternative air filter is indeed working
> > IN THAT APPLICATION... It depends on a person's priorities.
> > If you want performance then indeed the K&N is the
> > way to go but at what cost???
> >
> > And no, I do not work for a paper or glass air
> > filter manufacturing company nor do I have any affiliation
> > with anything directly or indirectly that could
> > benefit George Morrison as a result..
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