Bertrand Daoust

Jeez, those K&N filters don't get good press here!

I'm very happy with the stock one.
Never did anything wrong to the airbox on my car like the OP...
Not nice...

M. Requin

[My emphasis on the quote above.] Well, I have chimed in on every other K&N bashing so I guess I'll do it again. I live a mile away from asphalt, and if I had to use stock paper filters, I would get a $monthly subscription$. But my 86.5 came with a K&N, and I haven't replaced it in 60K miles, and people often remark how smooth my 928 seems to run. No MAF rebuild or anything else. Why did I stick with the K&N? Because back in the day I was a Honda-Norton-CZ-Guzzi bike dealer (a dealership I started in '70 which is still in business, BTW!) and we sold tons of them, and if used properly, they worked. Marine928's comments are exactly right, and I would boil it down to a maxim: if you don't know HOW to use them, you SHOULD NOT use them. I do have to note one thing though (as some others have done)- the fit is not great, and you have to be VERY careful to make sure the air box is completely closed when you remove/reinstall one of these filters. They (K&N) may have intended the close fit, but it is a PITA. YMMV, no commercial interest, etc etc...

WallyP

Several years ago, Dave Roberts ran back-to-back dyno tests with K&N and stock filters. Stock filter won. In addition, the air filter housings below the long-term K&N filters on customer cars were noticeably dirtier than those below stock filters. Dave quit selling them...

Speedtoys

More air = more dirt.


Pretty damned simple.

K&N is trash.

marine928

Dirt will not get by a properly fitted and prepared filter.....Period. You get more air because the volume passing through the filter is greater in a K&N. How can you say that an PROPERLY oiled filter will not attract and retain more dirt???
K&N are much better for high performance cars because the allow the engine to breath. The military, NASA, oxygen/nitrogen producers, CDC, hospitals etc, all use some type of liquid based filtration system when they need pure, clean air. There must be a reason. K&N go through rigorous internal and external testing under ISO standards. As far as W.P.'s testing goes, I have not seen the testing protocols so I can not comment on it.
All I can say is that if the K&N filter was prepped correctly and the fit was airtight then there is no logical way that dust could pass through the oiled filter without sticking to it. The molecular density of the oil is to great. Your talking several layers of oiled filter agent vs paper. Give me a break!

SeanR

Goddamn, you defend these crap filters like you work for them. If it works or you and makes you feel good, go for it. The rest of us who have dealt with the results of crappy filters will continue to do what we do too.

Speedtoys

Yes it will. Because it has to let something through.

Yes, more air = more flow over LESS area (way less surface area in a K&N than OEM) and that WILL pass more dirt.

EVERY TEST has proved this that everyone has publicly done.

So does the OEM filter that makes sick HP you will never make. So....why are you bothering again?[/QUOTE]


Annnnddd...those requirements are similar to your 928 case by case, how? That's the reason. Anecdotal evidence != Facts. Just good stories.[/QUOTE]


Of course it's tested. But it will not pass OEM filtration requirements. No public test has ever proven K&N anywhere near OEM filtration capable for ANY car.

Here, tests. With visible repeatable test definitions. One of MANY sources. K&N says they have done testing, but why would it be that their results are in direct conflict with dozens of more open, more publicly available and repeatable testing results?

All the testing says..is that a properly prepared filter that passes more AIR, will pass more dirt.

It's always fun to watch blaming "bad preparation" for dusty dirty intakes all over the world.

If it's so hard to do _that_, its junk.

And that's the best spin that can be put on it.


OEM filter filters BETTER, and flows more air than _you will ever need_.

..and can never be prepared wrong, and never fits wrong.


Isn't your 928 worth that?

marine928

Well Sean, I don't work for them but I do defend products that I think benefit our 928's. I have the PorKen tensioner, Constatine TT and clamp, Higher output alternator, air pump delete plus a few other improvements all of which have been maligned or championed by this forum.
You obviously love your paper filter and can't seem to get past the logic of "how stuff works". Paper is a "one dimensional" product and has its uses for some applications. If it was so good then the agencies' I mentioned that use "liquid" based filtration would not be doing so. Liquid filters naturally attract debris and are "multi" dimensional filters that are always used when high filter tolerances and air volume are required.
God#@$% you defend these crap paper filters like you work for them!!!

Speedtoys

How does a K&N benefit the 928.

This should be simple to lay out.

Chalkboss

Where is the filtration data for K/N? Rather than argue it is very simple to do a test and see what gets past the filter. If there is no data from K/N that is suspect right there. I have done particle size distribution tests with all kinds of filters and it's not rocket science.

Post a link if it's available, I would be interested to see it.

FBIII

I read these posts and do not see any supporting data for either camp! It has been predominately arguement by emotion.

Speedtoys

FBIII: I posted a URL with significant amounts of test results.

Not sure how you missed it, but here it is again.

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

marine928

I have never done any testing myself other than personal experience and working in an industry that spends millions to the right type of filtration. Clean air and lots of it is required by human and mechanical engines. Our own lungs use liquid based filtration and combustion depends on air as well.
Sure the K&N has filter in its dry state will allow more grit through, but when the oil is applied CORRECTLY and the fit is air tight dirt will be trapped. The main difference is that since the filter is multi dimensional vs one dimensional the volume is not decreased. Paper loses efficiency each day to a point that it could be sucked in depending on the intake pressure. Not good for our engines either. That's my story and I'm sticking to it.

Speedtoys

What benefits are observed with a K&N on a 928.

Should be a simple thing to lay out.

Chalkboss

A quick search- Here is what they publish:
http://www.knfilters.com/faq.htm#21

Interesting to see how that stacks up to air but I don't have the time to delve into it right now.