K/N Filter Test

[lht]

I was sent this the other day by an engineer I work with. I am really not liking K/N's after seeing this test.

www.duramax-diesel.com/spicer/index.htm

[John Lyon]

Unless I'm reading the graph backwards, the K&N did do well in the "resistance to flow" category (lowest?). Maybe this is where the racing reputation comes from, although apparently at the expense of longevity.

[Dr. Curve]

Yeah John, the K&N did fantastic in the "resistance to flow" arena............because it is not filtering out anything. It will almost let small birds come thru if they really are flying close by. What a wonderful and very revealing test. No wonder my bikes last so long.........I never have thought "wet gauze" would filter very well. Long live the paper filters we know and trust. K&N has always been a gimmick for the gullible.

[Steve Carlton]

[roger albert]

> because it is not filtering out anything. It will almost let small birds come thru if they really are flying close by.

Ahh yes, more rubish hyperbole.

The truly non gullible don't put all their trust in a single test done that pretty clearly had an agenda.

Meanwhile, my car, which has ran a K&N since 40,000 miles, is currently chugging towards 170,000. To be fair, it does use a bit of oil. About 3/4 of a quart every 6000 miles. Maybe my poor filtration is the cause of this horrible consumption.
Some of my cylinders are as far as 3psi from one another. Darn, I should have used paper. One of my other cars that was hotrodded and used a K&N had a motor (350ci) that was pretty shot by 140,000. Stupid 30 year old chevy. Oh how I've abused them. One of my airheads did need rings and valve lapping at about 105,000. I'll blame that on my K&N too.
I feel so deceived.

Have most of the guys with the SJ Powerfilter blown there motors already? Surely they have.

To be fair though, all sarcasm aside, the K&Ns are biased towards flow over maximum filtering. You have to pick the product best for you. The K&Ns are neither miracle workers nor outcasts. Just another product with its own particular set of tradeoffs. Just like everything else one buys.

[Dr. Curve]

Useless trivia.

[Sideshow_S]

Useless, but interesting. People fail to make the connection that on a bike, a K&N or Uni setup rids the airbox, which provided the most restriction for control and noise reduction purposes. That's where a lot of the power claims can be 'made'.

[roger albert]

> Useless trivia.

As opposed to Jimmy sciences such as:

> it is not filtering out anything (not ANYTHING?)

> It will almost let small birds come thru

> I never have thought

Well, you may have something on that last.

[peterz]

Some real data here (just one source, yes, but actual dyno runs, not anecdotal, seat of the pants data ), done with a R1100R and a K75.

http://www.eilenberger.net/R1100R/index.htm
http://www.eilenberger.net/k75exhaust/index.html

Quote from the K75 test:

"We also did a test of a stock air-filter with 50% of the filter area blocked by SaranWrap[tm] - it was a used stock paper filter. 50% blockage had no effect on the power the engine produced. We also ran tests of the K&N vs stock and the K&N vs no filter at all. Power remained the same. Any claims K&N make as to improving power must not apply to K bikes (the same results were found on K100 tests)."

-Peter

[John Lyon]

Check out AC Delco. Who would have ever thought GM knew what they were doing?

[Dr. Curve]

I'm with you John, and thanks to Peter for sending in what we already knew. K&N is a "feel good" product that sells well to the group of "under-cap" boys who want it...........but simply can't have it.

Paper filters really suck good while keeping grams and grams of abrasive materials from getting into your engine..........while K&N gauze strips simply invites everything in. More for people who don't shut the windows when it starts to rain........

Stick to a high quality paper unit. Power will remain strong and clean engine surfaces will be continued.

This thread is a good one for sheer exposure of semi fraud products that actually do nothing while costing a lot. Thanks to IHT for his thoughtful post.

[throttlemeister]

Utter BS. I don't know about things like flow, but I do have eyes. My bike came with a K&N, and while I wouldn't buy one myself, cleaning it is cheaper than getting a new OE filter. Simply put, my airbox is squeeky clean. No dust or debris in there. Nada. Zip. Running your finger along the inside of the airbox reveals no dust or larger particals either. And given that the inside of the airbox is always a bit greasy from the engine vent coming in there, dust or other crap that hits the walls doesn't move anywhere either anymore so it just accumelates. But again, there is nothing.

So, as a filter, it works just fine. Wether or not it improves performance, I don't know and don't really care.

Accusing people or companies of semi fraudulent activities is just plain wrong. Every friggin idiot with half a brain cell should be able to realize that a filter is always a trade off between catching particals and flowing air. Increase flow on the same surface area, you decrease filtering. Increase filtering, you decrease flow.

Just because something potentially filters less does not nessesarely mean it is bad for your engine, nor does it say the particals actually get through. That is also dependant on airbox, flow, intake placement and intake speed.

Having a pet peeve is one thing, accusing companies of malpractise is another.

Also, the biggest downside from paper filter is they dramatically reduce flow when they start clogging up with particals. A dirty paper filter makes your bike run like crap and needs to be replaced often and regularly. The only reason for OE's to use them is cause they are so cheap, not because they work so well.

[bigscience]

K&N's have two selling points I found attractive beyond the greater flow pitch; first they are supposed to stay clear and usable longer than teh stock paper filter so you don't have to get in there for maintainance as often. this I thought was due partially to the greater surface area on the K&N. Getting at the filter on the 11 is still one of my least favorite things to do and I guess the 12 has obviated this complaint by a nice accessable design so changing the filter is a ten minute joy. what this thread seems to be saying is that perhaps K&N achieve this effect by just not picking up as much dirt. clever.

the second thing is that the K&N's are reusable so that you never have to buy another for hte life of the bike. some long-term savings there as long as you plan on keeping the bike for a decade. the real benefit in this, I suppose, comes to the GS boys who (allegedly) operate in dust.

I guess a third reason I have K&N's on the 11's is because they came with the SJ powerfilter, which seemed to be a good idea at the time.

cheers

[R111S]

Caterpillar Marine Diesel Engines have K&N Air Filters mounted on them from the factory. I don't know the technical reasons for this but may be able to find out with a few calls to some Engine Division Engineers. I suspect it might have something to do with advantages in the Marine Environment versus paper (mold/salt air/humidity). I have one on my R1100S (K&N filter that is)...if it's good enough for Cat it's fine for me.

Here's one of our 1959 cu in, 1652 BHP, V-12 Marine Diesel Engines.

http://www.cat.com/cda/layout?m=53592&x=7

[roger albert]

You know CAT. Always doing things just to feel good.

> Paper filters really suck good

OK, I bow to Jim's superior engineering background and sucking expertise.

(Never mind that no filter ever sucks or invites - but that's the sort of "science" you'll get from someone with Jim's background and mindset)

> Every friggin idiot with half a brain cell should be able to realize that a filter is always a trade off between catching particals and flowing air.

Exactly, so if you don't get that...

[Deans BMW]

On the R1200S, Chris at San Jose BMW found that the addition of a K&N in place of stock A/F resulted in no HP increase. Running with out an A/F dropped the power, removing the snorkle dropped the power.

[roger albert]

That sounds about right. You'll normally see no benefit with stock motor, and a very small improvement with a heavily modified motor. It all boils down to how much margin was designed into the stocker. If it was a lot, then you'll be hard pressed to show an improvement.

[Dr. Curve]

There are a few born everyday.........and K&N has obviously found them. More power to them.........in their mind only, however.......as test after test has shown.

Still.......to each there own. Some need reassuring that they have really done something to improre their lot.......so a big flow aircleaner is as good a place as any to start. You boys that haveum......keepum. Us paperheads will do the same. Hell, in the old days we simply put panty hose over the velocity stacks, squirted some used oil on the layers and let her rip.......worked........at least as well as a K&N and was cheaper to.

[Dr. Curve]

Oh yeah, I forgot. The reason Cat uses wet filters on their marine engines is because the engine has more likely hood of getting wet. A paper filter does not do well once it is wet. The K&N on the other hand lets water, and anything else close by pass on thru so no problem. Marine use is often in clean air conditions unlike anything on land......but water mist and the like is often close by. No landuse CAT machine uses a K&N type filter but they are going toward the new glass filters being developed by Corning Glass Company, (GLW).

If I was running my bike like a jet ski I might switch..........but till then........well you get the picture.

[KeepTheShineyPartUp.com]

Originally posted by R111S
1959 cu in, 1652 BHP, V-12

Now THAT's what I'm talk'n about