IceY2K1

iTrader: (3)

Ok...so many people are throwing around BS that I have to get this off my chest. First of all, this is not a K&N vs. ALL. It's just that K&N has actual scientific DATA to back it up. NOBODY ELSE DOES!!! Okay? That's one big issue I have with all these I've seen this and I've seen that claims. Nobody, but K&N openly tests and publishes their data for ANYONE to call BS on:
http://www.knfilters.com/images/factstab1.gif
http://www.knfilters.com/images/factstab2.gif

So, first a little explaination of the SAE(Society of Automotive Engineers) J-726 test.
Okay so now that we know what a VALID test requires, I keep seeing this Apexi filter so called test from mkiv.com, which was a COPY from some Japanese site: http://www.mkiv.com/techarticles/filters_test/2/
I doubt this test was actually performed by MKIV.com:
http://www.mkiv.com/techarticles/fil...t/1/vacuum.jpg
So, my conclusion to the Apexi filter "test" is that FIRST this was not a VALID test according to SAE J-726 due to fact that the samples are not weighed before/after for efficiency %, time to a certain vacuum was not measured for pressure drop, and finally the filter sample was not a constant of say 5"x5" size. Second was that it's from a questionable source. This test was DEFINITELY not 100% unquestionable proof of diddly-squat, so PLEASE stop taking it as such. Plus, it's ONE test!!! Come on now, that's not proof of sheit.

Search the web and you will find TONS of K&N tests and data good AND bad to determine whether the K&N filter is YOUR best choice. Since most of us are too lazy, I'll copy two examples, since I don't have too much time today.

Ex#1: http://vettenet.org/knfilter.html
So, I concluded that K&N's are shown to match what % efficiency they claim according to the SAE standard, that OEM's such as Chrysler and Nissan approve of K&N's filtering capabilities, and finally that the size of the filter or more accurately, the filter area, determines the amount of time dirt buildup takes to reach a certain pressure drop.

Which brings me to the this point from K&N:
Assuming the Apexi is made of similar material, but with smaller "holes" to trap dirt because it doesn't have oil, then you would see a FASTER increasing pressure drop than a K&N. So if the Apexi and K&N begin to get dirty the K&N will flow more air, while the Apexi will get clogged and block airflow. However, only a vacuum test such as that used in the SAE J-726 test can determine how long this can take. I suspect the Apexi depends on surface loading due to it's ability to filter the smaller particles without using oil, so without depth loading like the K&N, this can cause the airflow to get blocked faster. So, if K&N recommends servicing at 50K miles, what does Apexi require?

Ex.#2: http://www.thedieselstop.com/content...20The%20Editor
So an independent lab(Southwest Research Institute in San Antonio, TX) tested the K&N as 99% efficient on particles from 0-5 micron up to 20 microns using a SAE J-726 with ISO Test Dust. Also, OEM minimum standard efficiency is 96%, whereas foam is only 80-85% unless it's very dense(read restrictive) or uses a "tack" agent such as oil to increase filtration without loss of airflow like AMSOIL does. The example also explains the "holes" and how they make the K&N filter efficient as stated here:This example also points out that K&N has been around for 30yrs. and began by making air filters for dirtbikes and off roaders, which are far more severe conditions than you'll see on the street. Also, they make filters for Chrylser/Mopar, Ford, Edelbrock, Rotax, Harley Davidson, and even Apache helicopters used in Desert Storm. All these companies would NOT use them if there was a BETTER alternative, especially since it would most likely be CHEAPER like a foam filter.

Just so you guys don't think this is ONLY a pro-K&N opinion:
AMSOIL's two-stage oiled foam filters are probably the BEST filter for stopping dirt MAYBE even better than an oiled OEM, but the pressure drop is probably going to be higher than an Apexi or K&N.



FINALLY, the K&N vs. ALL is a question about compromises. If you want ABSOLUTE power, go without a filter like drag cars. If you want ABSOLUTE filtration, go with an oiled OEM or AMSOIL's two-stage oiled foam filter. If you want something with good airflow AND good dirt filtration, you can't go wrong with a PROVEN K&N. Is there something better than a K&N? Most definitely. Is it an Apexi? I doubt it and until there is DEFINITIVE data proving it, I'll stick with K&N that gives more airflow than stock, provides great filtration, and is reusable FOREVER. My point is that each person needs to weigh their own needs/wants from a filter and choose one. Nobody has DEFINITIVELY proven ANYTHING about which filter is BEST to date, so don't buy the marketing hype and BS that people are spewing and try not to jump on the bandwagon when someone comes up with ONE or even a couple of so called "tests".




Sources:
http://www.seansa4page.com/resource/airfilter.html
http://www.performanceoiltechnology....testhedust.htm
http://www.thedieselstop.com/content...20The%20Editor
http://vettenet.org/knfilter.html
http://www.knfilters.com/facts.htm#MYTHS

jjs

WOW!!! You DID have alot to get off your chest!

As a happy K&N user for over a decade now, I am glad you took the time to put this post together.

IceY2K1

iTrader: (3)

There is NO WAY you read all that already!

Check out the links, they have LOTS of useful info.

jjs

No, not all the links, but over the course of the years and reading links on this topic, I have a very good idea where they would take me.

I DID read your whole narrative, etc. and again...thanks!

I have had a K&N of one form or another over the years in a 5.0l Mustang, VTEC Prelude, Dodge truck, Max and who knows down the road, but I do know I would very readily get another.

TZapper

Whew, a long but useful text.

On the side note, is Stillen Hi-Flow Air Intake = K&N Air Filter? If so, why not buy from K&N for cheaper than from Stillen. K&N filters claim to give 15 additional HP, so does that mean the Stillen Hi-Flow gives 15hp too?

Thanks.

IceY2K1

iTrader: (3)

I've used K&N's since age 11(25 now) on my Jet Ski and multiple dirtbikes. I still have my Jet Ski, so what does that tell ya? Haha. Anyways, I've always used a stock air filter or K&N on my Maxima. I've used a UNI foam filter now for a few years on a few different projects. The foam filter is VERY high flowing, however it's not very good at stopping dirt. I began to notice dirt in the intakes and even the engines at tear-downs. Finally, I started oiling the foam and haven't had a problems since. The performance difference between dry and oiled is miniscule from my experience.

IceY2K1

iTrader: (3)

Yes, but the Stillen includes a machined aluminum velocity stack to help smooth air.

scopium

plus stillen comes with all the bracets and other stuff u need for the install

PiotrC70

Some feedback for you w/ my experience....
I have some POS greddy filter that has been on my car since i bought it. My friend has an Apexi filter and although his car is a 91 and mine is a 93 and we have the same driving conditions, when we cleaned our air filters, mine had "SLIGHT" dust in the intake piping where as his was clean so the filter DOES definately make the difference, the other thing you face is getting possible hesitation w/ the k&n or any oiled filters. I don't think I'll ever go to an oiled filter again.

IceY2K1

iTrader: (3)

That's not DEFINITIVE proof of anything, but I'm willing to accept that an Apexi filter SHOULD be better than a dry foam Greddy. Dry foam filters flow, but don't filter much. There are some foam filters that are good, but they're either very restrictive or use oil.

You don't get a hesitation because of a K&N or an oiled filter.

Quicksilver

iTrader: (1)

I actually have a worse hesitation with the K&N right now, but I know it's not the culprit. I need to get the hesitation and lack of power TSB done.

IceY2K1

iTrader: (3)

It's not the K&N.

[edit]
Panel or cone?
[/edit]

foodmanry

iTrader: (15)

Is there any data linking a engine problem (like hesitation) with a K&N filter? I doubt it. Most people are making big assumptions.

CheshireCat76

iTrader: (1)

Very informative post Ice.
Question: Do you think its worth getting the Stillen
and the frankencar midpipe? Or just going with the full
frankencar intake kit? Basically..is the velocity stack
worth the extra money?

Thanks

NT2SHBBY

I have the Stillen and I love it...would I buy it again for $200? I dunno

IceY2K1

iTrader: (3)

I'm not sure if the velocity stack is the only difference. The K&N filter Steve uses looks smaller from the pics compared to the Stillen or JWT(if it's a K&N) cone. I haven't seen one in person though.

IF the filter has more area, then I think it's worth getting the JWT or Stillen with or without a mid-pipe.

Quicksilver

iTrader: (1)

I'm only running the panel. No intake as yet...

IceY2K1

iTrader: (3)

So you swap back and forth and can ABSOLUTELY tell a difference in lag?

If so, you got me on how a K&N would cause that UNLESS it's your mind playing tricks on you because of the sound difference.

Try having a friend swap back and forth without you knowing, while you test drive it with your stereo cranked up.

Quicksilver

iTrader: (1)

No, you must have misunderstood...

I know the K&N isn't the cause b/c both filters (stock and the K&N) have the hesitation, but it's actually worse right now, and the K&N just happens to be in it. I have switched it out without informing my wife and she tells me how/what it's doing. It might be the rising temperature and humidity here in GA, but then again, who knows with this drive by wire ****. I just know I need the TSB done, but I'm can't do it until I get my Dodge back from the machine shop (getting some serious head/intake work done).

IceY2K1

iTrader: (3)

Ok...then I stick with my original post.

It's not the K&N.

CheshireCat76

iTrader: (1)

Thanks for the reply.
Does anyone know if this is true? If it is bigger
will there be any fitment issues?

Thanks

ABS

Well, I read this thread and I just had to throw my 2 cents in. Let me being by stating that I have used a K&N panel filter and I absolutely will never by another again. Why do you ask? Because K&N filters, or any other non-paper filter for that matter, will let more silica (read sand/dust) than a paper filter. Forget about all the fancy tests for one moment and THINK! High flow filters obtain more flow with the same surface area in one way and only one way - they are more porous. There is no just way around that fact. Porosity of the filtering material is the key here. If you want better air flow, for improved performance, then go to a high flow (read more porous) filtering material. But don't be surprised when you start seeing black smoke from your exhaust by around 80-90k. There are really only four key factors that cause virtually all engine wear: 1. dirt entering the engine through the intake, 2. metal on metal contact when the engine is started without lubrication, 3. metal or dirt particles which are suspended in the oil and not removed by the oil filter, 4. old oil that has broken down due to absorbtion of dirt particles, water and multiple heating/cooling cycles.

If you are at all concerned with having your engine run in a condition which is as close to factory spec as possible (which is the key to long engine life), there are only three ways to make that happen: 1. Change oil and oil filter frequently, 2. Use a high quality oil and a very good oil filter, 3. Use the best filtering air filter you can find.

You may want to know what I saw with my K&N filter and you might be surprised. After about 20k, I cleaned my filter per K&N instructions and, before re-installing the filter, I held it up to bright sunlight. It was then that I saw, to my horror, lots of tiny pin holes in the cotton gauze material. Oil or no oil, dirt was going to get through that filter. Like a moron, and wanting the better performance, I ignored the condition and reinstalled the filter. Within 30k after that, I was seeing smoke from my exhaust. I was using Mobil 1 oil with 3k intervals and, what I now know were only moderately good Fram oil filters.

If you care about this question, and you want to be a test case, simply I dare you to do the following:

1. When still using your OEM air filter, drain your oil and send a sample to the lab to be tested to get a "baseline" reading. You'll get info on silica content (sand) and all kinds of metal content which are suspended in the oil. Bill99GXE can give you the info on where to send it . . . he even maintains an oil test results spreadsheet.
2. Then, do your oil change. Use the same exact oil filter. Install your K&N filter and drive for the same number of miles as before.
3. Take another oil sample and have it tested.
4. I would put money on it that your silica levels are going to be way up. Also, your suspended metals (from ring, valve, bearing and cylinder wall wear) will all have gone up too.

By the way, you might be interested to know that many people have begun suggesting that the issue isn't our OEM paper filters, but rather the air intake restrictions that are the major problem with our Maximas. If I were you, I'd keep that excellent filtering paper filter in place and mod the air box the the "ghetto air box" mod. This will get you much better air flow but will help to insure you don't need a new engine by 120k.

On the other hand, you could just believe K&N's internal research, which is probably questionable anyhow since they want you to buy their product! As I recall, their results for small dirt particles were pretty bad. In fact, the last time I looked, their testing was incomplete. I think Hastings had a pretty good article on how to test air filters for big trucks and it was far more detailed and involved than the K&N tests. As a side note, the engines in those big rigs are really expensive to rebuild so there is a LOT more emphasis on filtering capabilities in those . . .

Check out page 2 of this link on the .org, in it I gave my own analysis of the issues with the K&N filter with some interesting links . . .

http://forums.maxima.org/showthread....light=hastings

Like I said in the beginning, this is just my 2 cents, and I have absolutely no interest in starting a flame war. However, in regard to this particular question, for some of us, it probably pays to be prudent.

Good luck with whatever you decide.

iwannabmw

iTrader: (3)

I'm exhausted and it's going to be another early morning for me, so I'll just cut and paste a response I posted in another thread for now:

About the filtration: More surface area alone might allow more dirt to enter, but if the filter can trap more dirt and flow more air at the same time, that's a different story. Cosider these results for the cars that I'm responsible for: My 97 Max with a cone filter has Si readings of 7 and 9 for intervals of 8k. My 90 BMW with a cone filter had a Si reading of 5 at the 4300 mile sample. The 97 Altima I care for uses the stock paper filter. It had a Si reading of 6 at the 4400 mile point. Considering the BMW is mostly a track ride and lives at WOT, you'd think it would ingest more air Same mileage interval with a cone filter actually had less dirt than the paper one, and this on an engine that should have considerably more. One last data point is the 01 Legacy with the stock paper filter that had a Si reading of 13 at 5921 miles. I'll take the readings from the Max with the cone and the longer interval any day.

IceY2K1

iTrader: (3)

First, high flow filters increase air flow by INCREASING surface area to decrease the pressure drop across the filter NOT by just increasing pore size. Increasing surface area is accomplished by either a)making the filter larger or b)increasing the number of pleats and/or their size. Either a) or b) can increase airflow withOUT sacrificing filtration. Second, paper media is limited to surface loading due to its physical makeup, which restricts airflow especially once it gets dirty. Some high flow filters such as K&N use depth loading(multiple layers to trap dirt) along with larger pore size to increase airflow, while providing good filtration. Whether or not the depth loading with oil makes up for the larger pore size can ONLY be determined using the SAE J-726 or multiple oil analysis.

Engines that run OEM filters have this happen. PROVING it was caused by inadequate air filtration would be a long shot. Any number of factors could have caused or prevented damage such as changing the oil/filter more or less often.

I'll pass on this one, since it's too long for me to explain.

There are too many different factors that influence engine life, however there isn't "only three ways" and there are numerous "long drain" interval oil change analysis examples that prove otherwise.

I refer to my initial post.

How can you POSITIVELY relate the two? There are numerous factors that could cause those symptoms and unless you had the engine torn down and inspected, I doubt you could even remotely link the two.

What color smoke were/are you seeing?

There isn't a need to "dare" anyone since I'm currently working on this, but it will take some more mileage/time to gather the data.

The ghetto airbox mod seems like a good compromise, however you'll allow heated engine bay air into the engine which causes a different kind of damage and the air filter gets dirty much faster. A dirty filter will allow more dirt into the engine not to mention decrease air flow and negate performance.

K&N's internal research? All I've seen are 3rd party testing made public for ANYONE to disprove. Yes, they advertise that, but nobody else other than maybe Amsoil does this with their filters.

Not a flame back, but there are lots of assumptions and holes in your post I'd like to clarify for members to get the complete picture.

iwannabmw

iTrader: (3)

I'm glad you took the time to reply to the post in depth. I was too lazy

I agree with everything you mentioned, btw.

IceY2K1

iTrader: (3)

Oh no you don't! You better come up with something useful. Do you have any analysis's before/after a filter switch? I have ones that show the Si drop when switching to a new OEM, but I don't have any from the K&N.

BTW, do you have any information on the AMSOIL two-stage oiled foam filter? I'd really like to know more. Thanks.

slickrick

iTrader: (12)

nice post ice. but the ? still remains to me... does the K&N offer any kind of performance gain over oem? lets say screw filtration possibilities, but in overall performance will i feel or see a difference?

IceY2K1

iTrader: (3)

Yes. Import Tuner dynoed a 2000 Maxima SE with a K&N drop-in and gained 4.0hp/6.1tq, while NO FILTER gained 0.4hp/0.2tq over the K&N.

Will you feel that? I'd bet probably not by itself, but you will with say a Y-pipe and catback. It's more of a cumulative effect.

BTW, this car had a HKS exhaust(catback?) when dynoed with the K&N, so those numbers MIGHT be slightly inflated.

slickrick

iTrader: (12)

yeah. sounds fishy to me. i was just hoping by putting in a K&N it could make the difference between barely winning and winning vs. lets say a 330 but i feel the difference in filter would be negligible.

iwannabmw

iTrader: (3)

No analysis results before and after cone filters, just very impressive results with. For the best comparison, just look at my results at 8k and then look at every other 4th gen in the sheet.

I have no personal experience with Amsoil's air filters on any of my cars. The analysis results I've seen posted from people who have them look pretty impressive though.

ABS

I'm sorry that my response is going to be so long, but I'd hate not to answer all of your comments plus extend my own position on this topic. Before I begin, please recognize that nothing I state below is a personal attack and it is my hope that our discussion will benefit everyone on the .ORG.

Even if depth loading is a key aspect to K&N's design, even you admit that the pore size is larger. This goes precisely to my point. Large pore sizes allow a greater number of small particles into the engine. I am not positive about this since I do not own a K&N drop in filter for my Maxima, but I would bet that the total number of pleats isn't all that much different than the number of pleats in the OEM Nissan paper element. Also, I would argue that what you call "depth loading" is a misnomer. Only the parts of the filter that are outwardly exposed are going to trap dirt. If you are going to take the position that the dirt is sucked into the filter and might be caught in the 2nd or even the 3rd layer of cotton, then I would ask you this question: How can you be so sure that the dirt won't also get through that very thin and very porous third layer of cotton as well (then finding its way into your engine)? If K&N filters were made of only 1 layer of cotton, then they would have even more issues with dirt getting by the filter when compared to a single layer of paper. The fact is that a single layer paper is better than 3 layers of very thin cotton at filtering out the smallest particles. I might add that "surface loading" of both paper and cotton filter media helps to REDUCE the intake of dirt since in both cases the porosity of the material drops as it becomes loaded. Paper filters load faster which in turn means that a reduction in the intake of silica occurs faster than in a cotton gauze filter. I would add that I'm more than happy to pay the $20 every 15K for a new paper filter and that a change interval as frequent as this is probably sufficient to prevent excessive loading of the paper filter media except under the worst driving conditions.

Yes, that is true and since most people do use OEM filters, this wear is usually caused by other factors such as improper engine maintenance as I described in my last post. This would include such things as using poor oil, infrequent oil changes, poor selection of oil filter and/or air filter and any number of other variables such as driving habits and the quality of engine components. Nevertheless, would you agree or disagree with this question: Increased levels of silica in the engine and engine oil leads to increased levels of wear of the moving parts in an internal combustion engine? If your answer is "Yes" then if I can prove that K&N filters let in more silica wouldn't you be forced to admit that they are worse at actually filtering the air?

That's fine, I think we all have a pretty good idea of what causes engine wear . . . I gave some of the reasons in my last post and added a few to this one . . .


I do not want to be rude here, but I think you may have misread my statement. I was not describing factors impacting engine life, I was describing the factors that we, as owners of the car, have control over which can help EXTEND engine life. In regard to extended drain intervals, I believe there is a consensus that regular oil filter changes and a high quality oil (usually expensive synthetic) are required. This is consistent with all of my statements from my original post when I discussed factors which influence engine wear. If you disagree with me, then by all means feel free to to go 10k or 12k on a regular dino oil without changing your oil filter even once. Do that a couple of times and let's see what your oil tests show. I think Bill99GXE has some experience or knowledge with a test like this . . .

I see that you have chosen to ignore what is probably the absolute most significant issue with these K&N filters. Even after cleaning one and properly oiling it, I could clearly see sunlight through many pinholes in the cotton material. What do you think would happen to this filter after I applied some negative pressure to it? I'll tell you, it would happily allow lots of particles to pass right through those areas which had holes. I would extend my original statements and add that these were the holes large enough for me to see. That doesn't mean that there weren't many, many, more that I couldn't see but which would also allow very fine particles to pass through.

Actually, it is quite easy for me to relate the two. I was the original owner of the car, and I switched to Mobil 1 oil after about 3000 miles and changed it every 3000 miles thereafter. In addition, I performed my first dino change at 500 miles and another at 1000 miles and 2000 miles. I personally maintained the engine extremely well in every respect this included valve adjustments, timing adjustments, ignition system, air, fuel and oil filters, etc. In most cases, I was replacing filters at a rate much more frequent than that recommended by Honda. Furthermore, it is well known that Honda engines are very well constructed and frequently run for over 200k with no issues. This even goes for engines which have not been maintained at nearly the level I maintained this engine. The only realistic cause for what I experienced was the intake air filter.

I was seeing black smoke after approximately 30K with the K&N for the first 60K that I owned the car, with the paper filter, I never saw any smoke.

Perhaps I went to far with my "dare" however, I will not back away from my position. I would like to take this opportunity to rephrase my earlier statement and kindly suggest that the test defined in my first post would provide a reasonable benchmark for testing the validity of my statements. I will be interested in seeing the results of your tests once completed.

Depending on the location of the additional pickup tube, the GAB mod might or might not suck in hot air. I think many of us are already aware of the issues with "heat soak" that can be caused by pulling heated air through the air box.

Show me the 3rd party testing. I bet their methods are flawed and/or they are not reputable. Also, for the testing to be meaningful, we need some benchmarks to compare the results to.

K&N's internal research is a joke. Perhaps you can explain why they are only publishing the results of the "coarse particle" test and not the "fine particle" test? I would bet money that it is because the K&N filter performs horribly in the "fine particle" test. Could you imagine a company who's business is the production of filters not performing rigorous and in depth testing of their filters? Of course not. That is why this is so incredible. K&N knows the results are poor and that's why they won't publish them.

Just for comparison, here is a link to a Baldwin air filter for a truck engine (I misstated the reference to this link above when I mentioned Hastings).

http://www.baldwinfilter.com/engineer/97_2.html

Please take special note that this test is using the "fine particle" version of the test and not the coarse particles. Why do you think that is? Oh I also forgot to mention that the K&N test only measured pressure to 10" drop in water whereas the Baldwin test went to 3X that number - 30". Can you explain the reason why K&N isn't using as rigorous a test as Baldwin? It's pretty obvious to me that K&N is skimping on their tests intentionally. I'd even take it a step further, I bet that a 30" drop in water (due to the negative pressure) would probably pull dirt right through those soft and weak layers of cotton gauze! I'm not quite done yet. Read the K&N test notes carefully and you will see that the "initial" flow rate (meaning the initial negative pressure behind the filter) was much less at the beginning of the test. The Baldwin test has no mention of such a variance in pressure during their testing. This certainly poses the question: Why would K&N REDUCE the initial test pressure and then increase it later during their testing process? The answer is simple. The K&N filter would allow far more coarse particles to pass through the filter media at the start of the test - that is prior to the filter becoming partially loaded. As we have already determined, increased filter loading helps to "close up" some of those porous holes in the cotton gauze. K&N absolutely MUST do this in order to get good test results. If they started with high pressure right from the start, those coarse particles could literally rip right through that soft cotton, in turn making the filter even more porous. What K&N did in their testing process is the virtual equivalent of my taking a brand new K&N filter, sprinkling dirt all over one side of it and then applying a very mild pressure to the rear of the filter in order to pre-load the filter before putting it in my car. If I didn't perform this pre-loading, then, at a minimum, I'm guaranteed to pull a lot of dirt into my engine under high negative pressure conditions until the filter becomes loaded. Even worse, as I already mentioned, without the pre-loading, I also face the risk of creating even more holes in the already too porous cotton fiber media.

Just one last thing, the K&N tests are extremely misleading. A quick read of the results would make you think that K&N actually followed the SAE J726 testing process. However, an in depth reading shows nothing of the sort, all K&N did was use the standard "test box" from the SAE J726 test and instead they used the ISO 12130-1A4 test. In your post you mention that the standard for testing is the J726 test. Perhaps you can tell me why K&N did not use that test?

It sounded as if you wanted to discuss the facts of the matter, so I have done just that. Tell you what, contact K&N and get from them their test results for the J726 test with both fine and coarse particles and then we can analyze those results. I would bet money that they tell you they don't have those results (which I find impossible to believe) or, if they say they performed the test, they won't release the results to you (probably because of the uproar that would result from K&N customers everywhere once they saw the test results).

I strongly disagree with your last statement. The only "holes" we are talking about are those in the K&N filter. Yes, I am drawing some reasonable CONCLUSIONS based on a lack of available information. However, every conclusion I stated is based on a reasonable analysis of what is both known and unknown about the K&N filter products.

Trust me when I tell you that I would love to see a really well done scientific analysis of five or six filters, performed by a well respected lab. Unfortunately, I have yet to see any test results from an independent and trusted lab in the form of a detailed report. Of course, I would insist that the lab perform the full battery of available test, including the "fine particle" versions. If you have such test results or know where I can find the same, it would make for good reading and would end this discussion once and for all. I would only add that none of the links in the original post in this thread can be regarded as either reputable or complete. Until I see results such as I have described, my position remains unchanged.

Thanks for listening.

tarpoon

Started with the Apexi, and personally love it and never had any problems...

IceY2K1

iTrader: (3)

None taken.

K&N filters have varying pore size due to cloths physical properties. No filter has a homogenous pore structure, except some foam. Definitely not paper or cloth or anything that is of a "weave" type. That is exactly why the J-726 test procedure is used and companies manufacture J726 "dust" for testing purposes. All test dust has specific % of exact micron particles. Yes, larger pores allow a larger range of dirt particles to pass through, but if you have multiple layers a particle must travel through MULTIPLE obstacles which will increase the probability it gets trapped. Basically, a SINGLE layer filter has only one chance to trap a particle and that is why any single layer filter must rely on small pore size. However, a multilayer filter has MULTIPLE chances and therefore doesn't have to DEPEND on smaller pores. In other words, single layer filters only have surface loading as a defense, but multilayer filters have BOTH surface loading and depth loading. Even one of K&N's biggest critics claim depth loading is beneficial, " AMSOIL air filters distribute dirt throughout the foam depth, allowing unobstructed air intake to the engine." Depth loading is not some gimic K&N simply made up and the theory behind diffusion through the media, attraction of the particles to each other, and the path particles follow in airflow tend to agree.

K&N pleats are typically larger(taller?) and therefore fewer are used(See http://www.seansa4page.com/resource/airfilter.html) for a panel filter, which can decrease surface area. However, there are 3 or 4 layers over the entire surface area, which makes up for the lost surface area. Apparently, this is effective and surpasses OEM standards of 96% with 98%+ filtration. Now with a cone filter, you have a larger surface area vs. an OEM panel filter. That's what I mean when I say high flow filters use increased surface area to decrease the pressure drop. Panel filters don't have the room and there isn't any simple way to improve over the OEM on surface area inside the airbox.

Surface loading on paper filters causes an increase in pressure drop across the filter, which decreases airflow and increases the amount of dirt pulled through. There are more than a few example oil analyses on this, including mine and Blackstone supports this with their recommendations to change the air filter when Si levels reach a certain point. Yes, surface loading helps create more of a barrier by blocking all the larger "holes" first, the dirt particles follow the path of least resistance and therefore plug all the easy paths, ie larger pores. Once the surface begins to load, the K&N will allow depth loading, which is basically surface loading, but on SEVERAL surfaces. This along with the oil barrier allow the added filtration media to keep flowing, while an OEM paper would be limiting airflow. When this decrease in airflow occurs can only be determined through a J726 test procedure with a pressure drop meter. Yes, you can swap in a new paper filter every 15K, however even new it will not flow as well as even a dirty K&N.


Again, you can not link the two, it's impossible without a complete tear down of multiple engines. Also, there are other factors besides maintenance that cause failure. Infrequent oil changes and even crappy oil/air filters can be outweighed by changing the filters more often. Depending on your definition of infrequent oil changes, I'd disagree. Long-term drain intervals are PROVEN as long as a quality oil, dino or syn, are used with filter changes every 5K or less. Yes, K&N's are inferior to paper media filters for stopping dirt, I said that in my first post of this thread, "If you want ABSOLUTE filtration, go with an oiled OEM or AMSOIL's two-stage oiled foam filter.".

Yes, there are too many factors to consider here.

Yes, Bill has more than enough data to support most of what you said, however stating, "there are only three ways to make that happen: 1. Change oil and oil filter frequently, 2. Use a high quality oil and a very good oil filter, 3. Use the best filtering air filter you can find."…is a stretch since there are many ADDITIONAL ways to keep your engine in top running order, such as keeping it tuned and changing the fuel filter, PCV valves, 02-sensors, yada yada. Your 3-suggestions are good advice, but even 2) and 3) can be neglected and as long as you peform 1) around 3K miles religiously, you'll have a long engine life. As for going 10K-12K on a single filter, Bill has two analysis of the ULX-110 with one change that are within normal levels. So, it can be done. Would I, no. I'm very hard on my engines and I live in one of the most extreme and harsh driving conditions you can, ie desert which normally sees 100F+ temps including 125-130F. The damn "test dust" comes from pretty close to here! I didn't know that.

Oh…I’m not ignoring, I just don’t think I can explain it better than "So, what this proves is that you really cannot arrive at any intelligent conclusions by holding the filter to the light. That inspection is useless, pin holes are normal. In fact, those pin holes are what makes a K&N filter efficient. Within those holes, there are actually hundreds of microscopic fibers spanning them. When treated with oil, these fibers capture and hold the very fine particles. On the same hand, the fibers allow the filter to flow more air than paper or foam. Additionally, we have to understand that oiled fibers are translucent and are not easily visible to the naked eye." Your eyes can not accurately judge what is a good filter media. I agree common sense tells you visible "holes" are not going to stop dirt, however K&N's logic on this is more than acceptable considering I don't have a microscope to inspect if there are numerous cotton fibers spanning it and even IF that isn't true, based purely on the facts that K&N filters achieve a 98%+ efficiency at stopping dirt particles of varying sizes and there are numerous oil analyses that back it up in REAL WORLD DRIVING CONDITIONS. Also, when I look at my DIRTY K&N, I no longer see MOST, if any, of those holes. Why? Because they have been blocked by particles following the path of least resistance and now act as a barrier to prevent more dirt. That's why K&N filters increase in efficiency as they get dirty and exactly why K&N doesn't recommend you to clean them very often. A dirty K&N is a better barrier, yet flows more air. It's a compromise in the beginning, however once it gets "broken-in", it will provide more than adequate filtration as PROVEN by oil analyses.

Actually it’s impossible without a complete teardown of your engine and several other engines for comparison under varying conditions. First, no matter how well you maintain a car or how reliable the track record, you can still have mechanical failure. Changing your oil/filters frequently will decrease your chances of SOME failures, however you will NEVER eliminate the possibility. Second, white smoke would be attributed to the burning oil from a loss of sealing between the rings/cylinder wall, which COULD be caused by enough dirt over time. However, black smoke was most likely a sign of an improper air-fuel ratio. I'm not going to speculate on the root cause, since I'm not up to date on Honda ECU's and sensors. You can swear up and down that it was a cause of the inadequate air filtration, but you can’t possibly know that.


Agreed. I have two baselines and will probably have a third before I switch from the OEM panel to the K&N. I’m eager to also see what happens, but it takes me awhile to put on the mileage. It will happen though. IF the K&N does a bad job filtering with my 3K mile intervals under pretty much the harshest driving conditions, I'd be willing to give the Apexi a shot just to see if it's hype or not.

Cool. I guess I shouldn’t have assumed version 7.0 or whatever we’re up to now. Hehe.

Why are you so skeptical about their 3rd party testing? Flawed? Not reputable? You must understand that MILLIONS of people use K&N filters INCLUDING THE US GOVERNMENT!!!! Let me explain something about the military standard, ie MIL spec, for short. The US military is a HUGE consumer and they don’t accept BS from anyone, especially suppliers of parts they use for their multi-million dollar turbine engines(you think those truck engines are expensive? Ha!). I know this for fact and struggle EVERY FUKING DAY with it. These guys come up with the most **** retentive rigorous testing standards by far more stringent than the automotive industry. Just to keep this short, trust me when I say you can feel secure that if they use it, it’s good enough for pretty much the harshest conditions you can throw at it. Yes, the military K&N filters are probably magnitudes better than anything we can get, however if the military accepts such things as multilayer filters that utilize your so called “misnomer” of depth loading vs. a single layer paper filter’s surface loading, what do you think?

Coarse Test Dust, which includes particles ranging in size from less than 5.5 microns to 176 microns is more than adequate and AN INDUSTRY STANDARD AMONG FILTER MANUFACTURERS. You don’t need to worry about sub 5-micron particles causing negligible damage. Your average oil filters are lucky to stop contaminants smaller than 20-microns and they are made of paper.

Foam media can provide a better dirt particle barrier then cloth or even paper. Coarse dust is what the filter industry generally uses. These guys are just specifically testing to their filters ability NOT necessarily what you will require in general use. How does this prove paper vs. K&N? It doesn't.

Yes, it's not necessary. The general filter industry doesn’t use 30", so you can't compare apples to apples. 30" just allows you to see what happens to the efficiency of the filter from 10"-30" of pressure drop, which is outside the recommeded service interval limits. You could run a K&N past 10", however it's not realistic nor recommended because it can distort a K&N filter and allow air to bypass the filter. It's more of a filter integrity issue NOT how well the filter performs. If the general filter industry including OEMs and SAE accept 10", then that is enough to provide a % efficiency so that K&N can recommend 50K miles between cleanings. Why would you need to know above that? Simple, you don't.

That is specified in the J726 test procedure to equalize the pressure drop, which will vary from filter to filter to make the playing field equal. It's not a trick to improve their numbers. Baldwin most likely also does it, but didn’t report it. 3rd party testers will report MORE information then you need, so that's why K&N has that. Why else would they OPENLY publish that if it was to K&N's advantage and people would call them on it? That's right, they would HIDE it.

IceY2K1

iTrader: (3)

No, actually BOTH paper and K&N increase filtration efficiency as surface loading occurs, so saying K&N "absolutely MUST do this in order to get good test results" is not accurate. All filters are tested to 10" of pressure drop and the % of dirt is measured. The % efficiency of the filter is calculated once that point is reached, so it doesn't matter if it initially allows more/less dirt to pass and then changes during the test. It's a cumulative measurement of the filters' ability over the complete test cycle.

You're misunderstanding that ISO 12130-1 is a specification of four types of test dust A1, A2, A3, and A4. The SAE J726 is a test procedure and ISO 12130-1, A4 is simply the modern classification for the SAE Coarse Test Dust used in that time period. A simple time line explains why, "- ISO 12103-1,A4 Coarse Test Dust is nominal 0-180 micron size. ISO Coarse Test Dust is identical to SAE Coarse Test Dust produced by Powder Technology Inc. prior to formation of this Standard. The basis for acceptable particle size limits specified per ISO 12103-1,A4 were derived from analysis of 8 batches of SAE Coarse Test Dust manufactured between 1992 and 1994.". PTI took over manufacturing test dust for the industry from AC Spark Plug(a division of General Motors Corporation) with their cheaper better process. No magic dust here.

Facts or assumptions on peoples' opinions? I'd say the later. Fine dust is not necessary nor universally required. 30yrs. of being the top dog in the air filter business counts for something in this case. These guys couldn’t deceive MILLIONS of consumers for that long and never get called on it. It’s just not realistic. These guys started out making filters for off-road engines and they are still the most popular for EXTREMELY severe dusty conditions. Nobody claims that K&N won't hold up. Wonder why?

No, I was talking about compromises between filters and not jumping to conclusions when there is NOT enough data to know fact from fiction. You threw in your "2 cents" along with MANY assumptions that are not proven to be facts(engine care vs. engine life) and you based a good portion of your assumptions on the IMPOSSIBLE so called link to "holes" in YOUR K&N filter causing "black smoke". I have clearly stated that this was fiction and not fact, which brought about lots of fact-finding BS that I have to track down and disprove or clarify for the intended audience. You can't just make ASSumptions like you did and expect people to take them as FACTS. It's not going to happen here.

Good luck! Anyone who basis their opinion on such a random conglomeration of assumptions could never realistically be expected to change their position, since it’s not based on facts. How could you? You need to understand that even with your "five or six filter, scientific analysis", the results would NEVER be black and white. You can't expect a clear winner, because there isn't one. Each filter will have its positives AND negatives and it's all about the CONSUMER deciding on what he's willing to compromise on.