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Does anybody have experiences with K&N air filters for using in 08 or 07 R1200R? Besides being re-usable what are the advantages of installing these air filters?
Thanks in advance for any comments
Red Baron

Besides being reusable - reputable tests I've seen (and done) have shown no additional power from using a K&N, and they allow more dirt into the engine. They also tend to downstream oil from the oiled media, which gunks up (tech term) the throttle bodies.

All in all - they're garbage. I've taken them out of bikes I've owned and thrown them away.

A stock filter is cheap enough for me to replace it every 24,000 miles or so (actually did mine when I was having the brake-line recall done since it was "exposed" and the mechanic was right there.. the old one still looked good for lots more miles..)

I would like to see the study that says it lets more dirt in i have used them in Baja and in every vehicle that i have had for at leased 15 years i think you are giving out misleading info.

Here's one study:

http://www.bobistheoilguy.com/airfilter/airtest1.htm

"That said, both the cotton gauze type (K&N) and foam filters (Amsoil & Jackson Racing) showed the same levels of filtration. Both performed poorly compared to the fiberous or paper filters (Napa, Baldwin, and Mazda). "

That test is very illuminating.

Too bad he didn't do a dyno test on the car. With the pressure drop change so minimal, and the dirt differential so high, there would have to be an appreciable difference in power to make it worth switching to an aftermarket serviceable filter.

I will not be buying any more of them in any case.

garydbryson wrote:I would like to see the study that says it lets more dirt in i have used them in Baja and in every vehicle that i have had for at leased 15 years i think you are giving out misleading info.

You're certainly entitled to believe whatever you like. I'll believe the studies I've seen. I'm not so broke that I have to save on air filters.. If you want to see the power/vs/filter studies, there are the ones I did a dyno.. you can find some on the IBMWR website under K-tech (where there was no additional power with a K&N filter vs a used stock filter vs NO filter at all) and on my personal website.

http://www.ibmwr.org/ktech/dyno/index.shtml
http://www.eilenberger.net/R1100R/index.htm

For other studies on filter efficiency:

http://www.bmwe34.net/E34main/Upgrade/Air_filter.htm

http://home.stny.rr.com/jbplock/ISO5011/SPICER.htm - one of the most detailed.

There also was a study done where oil samples from an industrial equipment engine (grader if I remember correctly) were analyzed with the stock paper filters and with K&N filters. The operator of the equipment was really interested in using the K&N filters since he was paying through the nose for the paper filters that plugged up quickly in the dusty environment the equipment was operated in. His oil test results showed hugely increased silica (sand) content in the engine oil on the engine when the K&N filter was used. He gave up on the K&N and went to a two-stage paper filter design, which at least increased the time between filter changes for him.

A K&N might be useful for a Baja-1000 bike since it can get wet and still work (paper filters tend to collapse), and someone running the Baja only needs the engine to last for the race, but for the average steet bike, it provides no more power (BMW is awfully good at designing things like filters and exhausts actually..) and increases dirt getting into the engine.

Like I said - feel free to believe whatever you want, but a K&N will never be on any vehicle I own..

Don't confuse us with facts Don. The advertisments for K&N say they're the world's best air filter, so they must be!

For several years I regularly sent oil samples to the Kendall Oil lab for analysis at every oil change on all my vehicles. Somewhere in the basement of our Massachusetts home I still have the old reports in 3-ring binders. What happened to the oil when K&N filters were fitted is that silica levels increased in all cases. Note that I repeated this experiment many times on both motorcycles and autos and in all cases the results were consistent. This was over a period of years and covered a lot of tests. The conclusion was clear that K&N filters are not as effective at filtering out dirt as conventional paper element filters. I can't comment on power differences because I never conducted tests, although subjectively the difference seemed negligible. I can tell you that in all cases when K&N filters were fitted, air induction noise increased. Upon convincing myself that the K&N filters were less effective at filtering out dirt, the primary purpose of having an air filter, I quit using them.

Bill

Is anyone else curious why "garydbryson" only posted that one message disputing opinions (and fact) on K&N filters?

I find it a bit odd.. he never seems to have come back.

It looks like the only logical thing he could have to say after your large link filled response was " My mistake , Looks like you are right." Maybe he didn't want to do that. Maybe I'm wrong.

Mark

Seeing that that was GaryB's first post, and his first (and maybe last) day on the list, maybe he was in awe at the superfluous amount of information that is sometimes available on this list. He's most likely still digesting all those charts and graphs. I've run KN's in a few bikes that went 100,000 miles and were sold in good running condition and not burning oil. They were older bikes (maybe like Garys) and the aftermarket filters were most likely an improvement over the stock equipment. As far as the new bikes, I doubt that you could improve too much over the stock filters as the new engines seem to be extremely efficient in moving air thru them (intake and exhaust). Old habits die hard and K&N spends a lot on advertising

An air filter of any media needs to have enough area to flow a full volume of air at wide open throttle. That said, because of noise and emission laws, and the fact that most people don't ride at full throttle all the time, compromises are made because big air boxes, and big air filters just don't fit and arn't necessary. If you have a paper filter with enough volume no changes are necessary. Where a K&N or a foam filter has the advantage they will flow more air with the same area (because) they don't filter small particals as well as cellulose media does and they don't clog as fast. Cummins did a study on filter media a few years ago, other than a oil bath filter, a celulose filter with a large enough volume was found to do the best job. Diesels run at wide open throttle all the time so they need a good filter, and thats generaly the paper ones.

Ken G.

Settle down boys: I meant a real lab test. Don't worry i'm not going anywhere. Just want all the facts first___GB

Car gets the cheapo. BMW gets factory. Just not the Oil filters. OH OH, her we go again!
Thanks for the studies. Never tried K&N but my neighbors all use them in their work trucks.

Hi Guys: If you will go to page 3 the K&N story that you had ask for is there--Thanks for waiting___GB

garydbryson wrote:Hi Guys: If you will go to page 3 the K&N story that you had ask for is there--Thanks for waiting___GB

Hi Gary - page 3 of where?

Don: Just click on page 3 on this blog and it's under K&N ___GB

Red,
I use an Aussie foam filter made by Unifilter. It has foam pods where the OEM one goes and a pre filter which fits in the snorkel intake. When in use, the pre filter can be cleaned every 2000 miles and 2 are supplied with the kit to enable quick interchange. At 6000 mile services I have yet to have any dirt come out of the main filter when bathed in turps. It remains very clean indeed , whilst providing good flow (so long as it's not over oiled).

These are available in the US through Bob at Atlanta BMW. Check ADVrider and do a search on his dyno results with this filter.

Regards Mick.

garydbryson wrote:Don: Just click on page 3 on this blog and it's under K&N ___GB

Hi Gary,

I'm still confused. Think you could copy and paste the link?

TIA!

It's no use Gary, you've poked a stick into the biggest nest of data-wranglers I've ever encountered. Resistance is futile!