I need some proof/tests showing K&Ns poor filtration

[Mr_RPM]

So last night I got into this argument with a friend about K&Ns. He basically thinks they are the best all around.

beside the fact that my 4.0 I6 wont improve in performance/MPGs because the flow is not needed on a stock 4.0 because the intake system provides more air then the engine can use, but i also tried telling him that they don't filter very good compared to paper or even foam.

He works at car quest and thinks hes a mechanic (very smart, but not a mechanic lol) and claims he talks to all these filter reps and they all say K&N flows and filters better then anyone else. (who are paid to say so...lol)
Hes fallen to all these advertisements and K&N sponsored testing.

he then makes fun of me because I get all my proof from forums and thinks Im just full of false info from a bunch of rednecks and wannabes.

so, can you guys help me out and maybe shoot me some links to some facts, testing, testimonials, ANYTHING revealing the truth. Im just trying to prove that they don't filter nearly as well as paper. Im not worried about bringing flow into the equation as every engine is different.
I even try telling him to hold each filter in front of a light and you can blatantly see openings for the dirt to go threw, he then tries saying after oiling it you wont have that.
thanks guys =)

even if I cant get it threw his head, i atleast want him to second guess in his mind.

[Nightmare]

My rule of thumb is to only run any K&N filter on the street, or in the winter I would run them on atv and trikes, because dust and dirt usually arent an issue in the snow.
I won't run K&N for dirt or mud, not saying they can't handle it. I just won't.
I have run K&N drop in filters in every vehichle I have ever owned. I gained 1 mpg on the highway with my old car mitsubishi eclipse and about.5 mpg with my 2004 4.0 ranger.

Your statment saying they do not filter as well as paper and foam, is obvious. Hold up a paper or foam filter to the light, you probably can not see through it. Hold a K&N to the light and you see small specs of light in some places.
I know people that have run a K&N filter for the life of an car, and never had an issue. So I personally would not even get involved with the debate. This kind of topic is almost as bad as politics.

[swifty]

car craft did a test between k&n- paper- foam filters the paper beat the k&n im pretty sure. try to google it maybe it will come up

[Twilight]

http://www.pilotodyssey.com/PO/viewtopic.php?p=35119#35119

Here's some pretty good proof!

[Flossyb20]

http://www.pilotodyssey.com/PO/viewt...?p=35119#35119

Here's some pretty good proof!


That filter on that link has been severly neglected. K&N filters work just fine...if you maintain it. The oil is what grabs all those fine particles you see in there. Judging by the damage to the carb slide, this guy ran this thing for a while, through fine sand and everything esle, without ever cleaning that thing out. Now I agree that paper filters keep your engine cleaner, if you change them, but a K&N does flow better, and will work fine if you maintain them.

[cr480r]

My rule of thumb is to only run any K&N filter on the street

good choice

[Twilight]

Show me the flow numbers from K&N, then I'll believe they flow better.

[Twilight]

http://www.pilotodyssey.com/PO/viewtopic.php?f=9&t=5491

Here's another link.

[NINJA]

BaHaHaHaHaHaaaa, here we go again with peeps hating on the K&Ns. Go ahead and run your paper filters. Everyone should breath through a straw.....

[oldskool83]

had a k&n in my 300ex, 3 rides later in the dusty corn and soybean fields when the bike was starting to ping i went thru the carb and there was dust it the carb. the pinging was not due to the filter but the fuel. i went back to a uni filter checked it 3 more rides later and carb was clean.

k&n for street, nothing else im sorry

[Dammit!]

I ran my own flow experiment on a 250R. K&N in the airbox with no lid versus Uni attached right to the carb with no airbox. I had been running the K&N with a 178 main jet. When I switched to the Uni it sputtered until I dropped the main jet down to a 175. That was proof enough for me that the K&N does indeed flow more air.

Filtration wise, K&N will do just fine when maintained right. You really have to oil them correctly and get in the grooves without being afraid to over oil it (I don't think it's possible to over oil them really... I even spray the inside). I ride in the sandiest and dustiest conditions imagineable and never had any air filter related engine problems. Ever.

Edit: I will add that I do clean my K&N in my R a lot more often than I clean the Uni in my 350x. If your lazy about maintenance, get a Uni and leave the lid on.

[Dirtcrasher]

Point is that unless oiled correctly, they are junk. But it isn't THEIR fault dirt is being let in.

Many guys run them properly oiled and with an outerwears in the desert with few problems, and have PLENTY of fresh air that allows you to jet up in most cases.

[cr480r]

I ran my own flow experiment on a 250R. K&N in the airbox with no lid versus Uni attached right to the carb with no airbox. I had been running the K&N with a 178 main jet. When I switched to the Uni it sputtered until I dropped the main jet down to a 175. That was proof enough for me that the K&N does indeed flow more air.

Not a very accurate test at all... a true test would be testing both types of elements in the SAME box....

As for filtration you can only put as much oil as there is gauze.. many brand new k&ns have holes in the gauze that daylight can pass through.. as well as sand.. last time i checked oil didnt plug holes... K&N oil sucks.. foam filters can use the thick sticky stuff for max filtration in harse enviroments..

[The Goat]

you want a test...look through a foam filter at a light... look through a k&N at a light... a tshirt would filter better.

[Twilight]

Goat!!! Where the **** you been bro?

[Dammit!]

Not a very accurate test at all... a true test would be testing both types of elements in the SAME box....

As for filtration you can only put as much oil as there is gauze.. many brand new k&ns have holes in the gauze that daylight can pass through.. as well as sand.. last time i checked oil didnt plug holes... K&N oil sucks.. foam filters can use the thick sticky stuff for max filtration in harse enviroments..


Why is it so easy for people to say "there's daylight shining through it so it must let more dirt through" but they can't admit that they also let more AIR through? If these things are SO wide open and let so much crap through then how do they NOT flow more air? I can breath more easily through a t-shirt than I can a pillow. :lol:

Bottom line for me is I've been using them since the 80's and NEVER had a problem with them despite the conditions they've been used in. If they didn't work and let tons of sand and dirt through I'd be rebuilding engines constantly. You know how many times the top end has been rebuilt on my R that I've owned since 1989? Once. And it's not a gently used machine.

P.S. I don't use K&N oil. I use PJ1. :p

[Mr_RPM]

not doubt K&Ns flow better then most/anything. But with research I have found that on my wrangler 4.0L the extra flow does nothing because the stock system with paper filter supplies more then enough air to the stock 4.0 I6. so my argument was putting on a K&N would have no advantage on MY PARTICULAR model of automobile (while most cars would really improve from some better flow, they designed TJ's air system to not be restrictive for the stock engine) with the debated disadvantage of letting more dirt in.
Im not worried about flow, but more about clean air, but it seems theres to many variables to get black and white results.

[2Tim215]

I don't have the experience to really add much but it does seem to boil down to the proper care of what ever filter you use. I have made my own filters that I attached with zip ties using Air Conditioner filter foam. It is less dense than stock foam filters and breath's fine. Holds the oil well and haven't had no issues. Unfortunately I have bought to many trikes that had deteriorated foam filters or none at all and not knowing what might roll in next its always good to have my filter material on hand. I don't have any sandy areas where I ride, mostly dirt, mud, and snow, with occasional dust on the dry days, (or when the person in front of me is ripping it up!) I'm in Farm country and a lot of Utility style trikes pop up.

[cr480r]

Why is it so easy for people to say "there's daylight shining through it so it must let more dirt through" but they can't admit that they also let more AIR through? If these things are SO wide open and let so much crap through then how do they NOT flow more air? I can breath more easily through a t-shirt than I can a pillow. :lol:

Its not hard to see that a K&N probably could pass more air for a given surface area, but your test example of the two was bogus.. Sure the results may have been the same in an accurate test, but yours was not.. Its easy for me to say K&Ns dont filter well because i had a NEW K&N that had very small holes in it.. and surprisingly it let sand through.. Enough for me to take it off for good. I'm glad your k&ns have worked well for you and others, but the reality is they are not a great filter.. You'll never see an oiled gauze type filter on any heavy, industrial, or farm equipment... Theres a reason for that.. its too bad because a reusable filter could save alot of money for commercial fleets..


But with research I have found that on my wrangler 4.0L the extra flow does nothing because the stock system with paper filter supplies more then enough air to the stock 4.0 I6. so my argument was putting on a K&N would have no advantage on MY PARTICULAR model of automobile.

Yes, I agree in order for more airflow potential to provide gains, the previous setup would have to be insufficient. A simple way to test on a automobile is to remove the filter completely and test for gains.. Most vehicles have plenty of filter capacity and added flow potential adds nothing... and those that dont can usually benefit from an entirely new air intake system to eliminate restrictive ducting. Its amazing how many people really think they gained 20hp from an element because its says so on the box..lol

[SWIGIN]

I have no test but I do have a ton of experience with both K$N and foam filters on ATVs. I've rode since the early 80s and I can tell you without a doubt that in off road riding K&N does let in more dust. I say dust and not dirt because thats what it is. I also, when I raced, would never use a K&N on my 2 strokes. My brother did and his intake tube was always filthy compared to mine with a 2 layer UNI. As far as 4 strokes go I will only run K&N, I guess my main reason for doing this was that a 2 stroke race motor is more likely to waste a top end and I wanted the best filter I could get my hands on as far as stopping dust. I have had 4 stoke motors run for well over 10 years and they ran fine till I sold them.

Basically, this debate, from what I've seen is a waste of time. The K&N does let more dust in but it's really no big deal IF you are trying to get every last ounce of air into a race motor. On a stock motor I'd just stick to foam.....or paper in this case.

[Mosh]

I run 2 85 r's with no lids.
one runs a Uni.
One runs a K&N.

After the same riding trip, with my wife and I both riding the 250R's , running the same trails, in dusty conditions, My airbox tube has more sediment, than the Uni on hers.
Both are oiled properly and sealed well.
I usually lead which creates more dust for her to follow through and she still gets less dirt in the intake tube.
However, the K&N fitted tighter on the airbox lip and got a better seal. the Uni was hard to get a good clamp on.

The K&N lets more particualtes through IMO. This is something I started monitoring last year.
Neither filter runs a outerwear. Now that I have the Dirtcrasher aribox support rings, I am going to re monitor the testing. Both intake tubes were removed this winter and cleaned extensively. So it should be a fair test.
I will report back after the first ride which will be sometime in spring.

http://i100.photobucket.com/albums/m40/cosmicquads/IMG_1950.jpg

[mudbogger]

http://www.pilotodyssey.com/PO/viewtopic.php?f=9&t=5491

We have a pretty good thread going on there about K&N filters might be a good read.If you need to join it is free, and you can just delete your account if needed after reading.I use K&N filters as a PRE-FILTER for my Pilot, and as detailed on the thread you can see the main fikter is basicly clean as when it was put in,works well.I would never use a K&N as a main filter, with or without a Outerwear.Read the thread if you can it has a lot of good stuff.

[SWIGIN]

I run 2 85 r's with no lids.
one runs a Uni.
One runs a K&N.

After the same riding trip, with my wife and I both riding the 250R's , running the same trails, in dusty conditions, My airbox tube has more sediment, than the Uni on hers.
Both are oiled properly and sealed well.
I usually lead which creates more dust for her to follow through and she still gets less dirt in the intake tube.
However, the K&N fitted tighter on the airbox lip and got a better seal. the Uni was hard to get a good clamp on.

The K&N lets more particualtes through IMO. This is something I started monitoring last year.
Neither filter runs a outerwear. Now that I have the Dirtcrasher aribox support rings, I am going to re monitor the testing. Both intake tubes were removed this winter and cleaned extensively. So it should be a fair test.
I will report back after the first ride which will be sometime in spring.

http://i100.photobucket.com/albums/m40/cosmicquads/IMG_1950.jpg

Go ahead Mosh but like I said in my post, I know which one will be dirtier.

I ran this test in the 90s and I'd bet that the dirt/dust has not changed in size...lol

[fabiodriven]

I have a K&N on my R. It is a pod type filter with no airbox.

I am going to say right now that what I did to this filter was above and beyond what it is designed for but I just figured I'd share my experience.

I was riding the R about a month and a half ago. It was really cold out and there were a few slushy puddles around. I was doing my best to slow down and avoid the puddles but I couldn't miss them all. At one point she sucked up a good swig of water and died. After kicking 'er over for a while it became obvious that she wasn't starting. Luckily somebody had some tools and WD-40, so I removed the filter and what I saw made me gasp. Muddy, icky water in the intake horn of my carb. It had flowed right through the filter and into my motor. Eventually I got everything straightened out, but I will never forget what I saw in there.

Again, this filter was not made to stop what I was throwing at it. It is my fault the mud got in there.

K&N's are good on the street.

http://i146.photobucket.com/albums/r275/fabiodriven/300R/PB110093.jpg

[3Razors]

Same post I had on another thread here with more added to it:

I saw an independent test once, it was on a diesel forum where they tested 3 different types of airfilters paper (fram), foam (uni), and fabric (K&N). Wish I new the site, maybe someone can google search it.

The test had a tube with a vacuum that sucked air through it. On the end of the tube they clamped each filter on. Inside the tube they placed a piece of glass with a light coat of grease on it. After the vacuum was turned on they sprinkled sand and dirt with various degrees from fine to thick particles. The glass from each tube was compared to eachother.

The final verdict was that the paper filter protected the best and virtually nothing got through but had the poorest airflow. The fabric (K&N) had the worst amount of grit on the glass, about 4 times that of foam but flowed the best. The foam was declared the winner in that it had very little grit that passed through the filter but was the best compromise in high airflow.

All opinions and testing aside, just look at the design of a K/N for yourself. It is very thin 1/8 inch highly porous oily sock between wire mesh, compared to a oiled foam that has a full inch or so of protection for grit to try and pass through. Its a no-brainer what protects more. The paper elements are thin aswell but not porous by any means. Also most people that run k/n do so with an outerware to aid in filteration which has shown a 10% reduction in flow, so now the higher flow is negligable. Something to think about is if the K/N filtered that well in the first place then people wouldn't need to use an outerware. If you want more flow and best protection get a larger than than stock foam air filter with more surface area to give more volume of air. All factory teams run dual stage foam, I did the same long ago and never looked back.

[Bretmd94]

K&N have better flow, but it is because the holes are bigger! Yes they let dust through, seen it on my bikes running K&N's in the dust. I had changed to well oiled foam filters in dry conditions. It is more work having to clean it every ride, but no dust goes through.

Now in the dunes, I swap to my K&N. The Oregon dunes have large coarse grains of sand. K&N's almost seem like they are made for these conditions. Pull the airbox lid off, and run a pre filter with it. (yes I know filter for a filter seems dumb but sand will do bad things)

I do believe they let more air though, but they will let dust through as well.

[cr480r]

Now in the dunes, I swap to my K&N. The Oregon dunes have large coarse grains of sand. K&N's almost seem like they are made for these conditions. Pull the airbox lid off, and run a pre filter with it. (yes I know filter for a filter seems dumb but sand will do bad things).

It was Horsfall/Houser sand that went through my new 14x4 K&N. My buddy had Winchester sand go through both K&Ns on his sidedrafts. The outerwear is a good idea lol

[Bretmd94]

It was Horsfall/Houser sand that went through my new 14x4 K&N. My buddy had Winchester sand go through both K&Ns on his sidedrafts. The outerwear is a good idea lol

Oh yeah, always run an outerwear. Airbox lid off, outerwear, K&N. It gives great power but there is a reason.... bigger holes for air to go through in the filter, but bigger holes for sand/dust to go through as well.

This reminds me, I need to take my 250r in to have a look at the rings. After 2 seasons its still running great but I haven't been the best about maintenance.