K&N Facts and Myths

[RedWolf4000]

Here is a link I came across while searching the internet:

http://www.thedieselstop.com/contents/getitems.php3?K&N Letter to The Editor


i believe this to be the most accurate thing i have read about these filters Thus Far as they have never caused a problem and are THE HIGHEST QUALITY FILTER YOU CAN BUY.

 

[Ron Jeremy]

IMO, the worst quality filter you can buy. I tossed my K&N's and went to oiled foam in my truck and paper in my wife's and saw my si #'s plummet. With the K&N, I could literaly see a coating of dust in my truck's intake plenum past the filter. I'll take the evidence from my UOA's rather then the propaganda of a K&N tech.

 

[michaelc80]

quote:

---

Originally posted by Ron Jeremy:
IMO, the worst quality filter you can buy. I tossed my K&N's and went to oiled foam in my truck and paper in my wife's and saw my si #'s plummet.

---

It would be interesting to see what you're doing wrong with the K&N air filters. I have a K&N in each one of my Jeep 4.0's, and the silicone numbers are well below average with my UOA's in both vehicles. I cleaned and reoiled the filters at the same time I changed my oil, so I would have assumed that I might see elevated silicone levels with this UOA, but they were below average. All the other numbers were right in line too, so the K&N is doing it's job nicely. I also wipe the tube with a white terrycloth towel going from the airbox to the engine when I recharge the filter, and normally find no dirt whatsoever.

You didn't say what type of truck you had, so could it be that the design is just not a good design for a K&N filter, as opposed to a problem with the K&N filter itself? Did you follow the directions and clean/reoil it correctly?

 

[Mike D]

I've been curious about the K&N filters for some time and recently installed one in my new Ford Ranger pick-up. I've got almost 5K on the new filter and I was curious to see if the oil from the K&N would foul the MAF. Well, to make a long story short, It DID NOT! I have checked the "filtered" side of the air intake system every 1 thousand miles since installation to see if any oil or dirt particles could be found. I used a very fine woven and very soft piece of white cotton cloth to swab the intake system up to the intake plenum or manifold and then inspected this cloth under a very well lighted magnifying glass. I could find no particles(granted, the magnifying glass is not a microscope) and could see no discolorized cloth due to the oil I thought the filter would release. I did not rely on any other persons test to come to this conclusion, I did my own. I drive almost a thousand miles weekly and my driving includes dirt farm roads, gravel roads, blacktop and "chip and seal" roads, and of course the average concrete interstate. I believe the K&N to be a good filter and until I see a UOA with evidence pointing to the contrary, I'm staying with it. I will also continue to do the "white glove" test, although I believe I'll push the test samples out to 5,000 miles now instead of 1,000 mi. intervals. I now believe the K&N is a very good filter and I'm also of the opinion that if anyone has a bad experience with them, the problem is most likely something besides the K&N filter. I've had airbox seal problems before and on more than one model of truck. If anyone has a problem with dirt/contamination in the "filtered" side of their intake system, I'd recommend a very good inspection of the airbox or other intake duct. My 95 F250 with the 7.3L Powerstroke had this problem from the factory and it is well documented. Airboxes and ducting like every other vehicle part can have problems. I have not gained any noticeable hp or mpg as a result of the installation of the K&N filter, but, I didn't expect any either. What I was after was a good filter that would last the life of my truck and do an excellent filtration job with a reasonable amount of cleaning/maintenance. At the present time, I think I made the right choice.
My $.02

 

[RedWolf4000]

This site has made me very paranoid with all this air filter stuff. Fact is many people get great UOA results with a K&N, and they run the same tests that are run by the SAE for paper, with the same dirt/dust formulation. In results they get a 99% efficiency score.

I am sorry if some people have had bad results with K&N, but im sure it had to do with proper seat and sealing of the filter because the media does a perfectly fine job. Theres no trick or gimmick, its a true 99% efficiency, with a new, clean filter. This rating includes both fine and course dust, enough said.

The company has been in business a long time and people have been using them on engines without problem.

Its very EASY for a company like amsoil (just an example) to pick apart K&N by saying you can see "pin holes" and such through the media, and more air flow = more dirt. Amsoil wants to sell more filters!

Foam, Cotton guaze, and paper alike all filter excellent, we have seen the results from our very own UOA's. Dont go throwing away your K&N because of "Spicers" test results that we dont even know to be true. Think of all the variables that test went through, and all the people who dealt with it. My guess is it was done by a paper BIAS. Your UOA results show GOOD silicon levels with YOUR K&N.

You guys dont trust JOE-SHMOE to change your oil, then do not trust JOE-SHMOE to test your air filters for you.

My K&N filters 99.05% of the standard Dirt/Dust In the SAEs testing. It last the life of my vehicle (which will be a very long life)

I am happy.

 

[Ron Jeremy]

Right, I forgot about the pinging caused by a fouled MAF. BTW, I have an 4.6 L F-150. I will conceded that over-oiling the filter could be considered my fault, but I followed the cleaning/ re-oiling procedure to the letter. As for my wife's car, the si #'s were high from the K&N right out of the box, so it wasn't faulty servicing. Funny thing is that my Accel foam filter hasn't fouled my MAF and has delivered considerably lower si #'s as has the Purolater paper in my wife's car. So we can talk about how K&N's slickly marketed product is supposed to work and how they work in the real world. If they work for you, that is terrific, but I've seen far too much evidence in my vehicle, in friend's vehicles and on this site to ever consider using one again.

 

[Patman]

I've been one of the biggest anti K&N people in the past, however when I got my 98 Corvette and found out it has a K&N air filter, I decided to leave it in and see how the UOA looks first before just throwing it out.

A week ago I took off the airbox assembly so I could replace it with a modified Z06 Corvette airbox lid instead. I was pleasantly surprised that the insides of the intake looked completely spotless, the K&N wasn't letting any visual dust through like I've had in previous cars which used K&N filters. At the same time though, the factory airbox lid for my car did not have a very big opening for air to get through (I honestly don't know how this engine got any airflow into it!) but now with the new setup the air filter is a lot more exposed. So this will be the true test for this air filter to see how it performs.

I'm going to run my first interval to 5000 miles, and as always I will get Terry to interpret the results. The decision on whether or not I keep this K&N air filter in place or not will solely rest in his hands. If he feels it's safe, it will stay.

I definitely won't be cleaning it very often if I do keep it in though. Maybe once every 50-60k.

 

[XS650]

quote:

---

Originally posted by T-Keith:
K&N facts:

1. SAE test

---

It's common knowledge that K&Ns don't filter as well as a good paper filter, in the past, if you looked carefully at some of K&Ns own data you could see that.

The most interesting part of the test you linked to to me was the data showing that the K&N held a lot less dirt than the good paper filters before it got too restrictive. Higher dirt holding capacity has always been one of the things K&N touted. You could add that as another K&N myth.

 

[wn1998]

I too don't know why K&N filter users get so worked up when someone has a negaitive expirence with a K&N product. If someone has a bad expirence with a k&n the first post I see is "did you clean and oil it correctly?" Is it really that complicated, I don't think so.

I recently took my K&N cone filter out of my 99 Jeep Wrangler because I was uneasy about it's filtering capabilities after reading many posts on this board. I put in my old stock airbox and a AC delco paper filter.

I am not bashing the quality of K&N because I am not certain of how well they filter. However, I do know that the HP gains were not there. I see no difference in HP or MPG from my K&N Cone to my AC delco Paper filter and I am on my 4th tank since the switch.

Finally, I find it much easier to spend $10 every 6 months to drop in a brand new filter than to "re-charge" a K&N.

 

[crossbow]

One thing I've noticed (thanks to this site) is a lack of quality in K&N filters. After becoming extremely paranoid about the conical airfilter going on my mazda6's cold air intake, I decided to go with an SnB filter instead of the standard K&N.

http://www.sbfilters.com/home.htm

Some of the older posts pointed out that if you were going to go cotton gauze, you should really look into the SnB's...so I figured what the heck, and ordered one.

The difference in quality between the two is enormous. The K&N is very flimsy, with weak thin pleats that are easily bent (just in handling the filter) and the end support for the filter was soft plastic. It was also readily apparent that the K&N's pleats didn't go very deeply into the filter...just felt really cheap.

The SnB was the complete opposite. It had "more" pleats, which were deeper (over half an inch deeper) and the top and bottom of the filter was reinforced to hold all the pleats securely in place. The SnB also has an additional opening on the bottom (for all you airflow freaks).

Here's some photos, and the threads I took the information from.

K&N

SnB (1 Inch larger)

Note the end of the pleats on the K&N vs the SnB. The SnB's are tucked behind the reinforcement of the stiff caps.

Here's a bottom shot of the SnB.

Here's the threads...
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=15;t=000182
http://www.mcagraphix.com/filter/filtflow.htm
http://www.bobistheoilguy.com/airfilter/airtest3.htm
http://forum.mazda6tech.com/viewtopic.php?t=160&postdays=0&postorder=asc&start=0

More filter company links...
http://www.baldwinfilter.com/
http://www.unifilter.com/automotive.htm
http://www.sbfilters.com/home.htm


I purchased the filter from
http://www.intenseperformance.com/
With excellent service and speedy response to emails (on questions of the various SnB filter types).

Regretfully I never got around to do a UOA comparison between the K&N and SnB filter. I sold the cold air intake (with its filter) to another 6s member, and traded in my 03 6s ATX for an 04 6s MTX. On the new car I'm planning on going with a baldwin paper filter and will have a UOA on that gem in about 6k miles.

And here's a final photo for anyone curious as to why one would put a cold air intake on the car, and how it might work.

Look Ma! Air's coming from the wheel well, completely shielded from the engine heat, instead of 120F engine bay air! (For those curious, it dyno'd a 12 WHP peak gain, the new CP-E intake I'm getting dyno's a 25 WHP peak gain [combo A/F tuner and Intake])

[ August 29, 2004, 09:07 PM: Message edited by: crossbow ]

 

[RedWolf4000]

That is the best looking cotton guaze i have ever seen.

I want to make a point that when i speak of a K&N air filters efficiency i am talking about the drop in replacement, not the conical.

 

[sxg6]

snb looks identical to k&n style filters.. the first image of the k&n looks like it was improperly recharged, or is just old and lacking oil.

 

[T-Keith]

K&N facts:

1. SAE test

2. I used a K&N in my wife's car for several years. The seal is shot now, poor materials.

K&N myths:

1. You can get a straight, unbiased opinion from an employee of a company about their products.

K&N users get really worked up about these studies and try to discredit them, but I think those that do aren't thinking very clearly.

I was a dedicated K&N user until a few months ago. The studies and personal experience have turned me off.

Are they a good filter for race/fun cars with a good filter placement? Yes. Are they a good filter for a custom airbox? Yes, if you don't care much about wear. Will they save you money over time? Sometimes. Are they a good replacement for a paper filter in a daily driven car with an good airbox? No.

-T

 

[crossbow]

How can you say they look identical? Look at the pleats!!!!!

Comparing a K&N to a S&B is like comparing a Fram oil filter to a K&N oil filter

. Sure they both perform the same function, but one obviously has alot more quality and materials put into it.

Btw, that K&N filter had 5k miles on it when I replaced it...

 

[T-Keith]

The green filters look especially good too. Supposedly the seal is much better then the K&N.

Just a heads up on that CAI. The GTP guys refer to that as a Fenderwell intake, because the filter goes in the fenderwell. I personally wouldn't run that setup due to the amount of dirt, road debris, and even water that can easily enter the fenderwell.

-T

 

[crossbow]

quote:

---

Just a heads up on that CAI. The GTP guys refer to that as a Fenderwell intake, because the filter goes in the fenderwell. I personally wouldn't run that setup due to the amount of dirt, road debris, and even water that can easily enter the fenderwell.

---

Which is why I'm going to be using a baldwin paper filter now, and replacing it regularly. But ya you get a hella lot more debris, especially considering the 04's have open inserts and vents in the rear of the wheel well.

The filter is however "high up" in the fenderwell, which greatly reduces the direct spray or debris which occurs...its actually @ the stock height of the resonator. But I definitely understand your comments... Just no where else to run the filter...the short ram's people have actually REDUCE horsepower, as the intake air gets to almost 140F!!!! (Crazy Engine Bay Heat)

 

[T-Keith]

Most of the GTP run a short tube with a box to protect the filter from the heat and pull air from behind the headlight and fender areas.

It really works well and I'm suprised that most other car groups don't try somthing similar. I guess the companies are doing just fine making a 12 inch long tube with an open cone and selling it as a CAI.

-T

 

[crossbow]

Well its always more then just a tube...

For the same 18 inch tube...here's the WHP gains (verified by multiple members).

K&N 7 peak WHP
AEM 9-10 peak WHP
Injen 14-15 peak WHP
CP-E 25 peak WHP

If it was just a simple metal pipe with a cone filter on the end...why would all the gains be so varied? Intakes are as complicated as exhausts with the way the tube sizing is setup, where certain components are placed, etc etc. Raising or lowering the maf just a single mm has a major effect on how the sensor reads the incoming airflow, which can determine how your A/F ratio is effected.

You don't get this type of torque gain from a simple pipe

.

 

[T-Keith]

On Some cars you do.

What I'm getting at though is that no intake that draws air from the engine compartment is a "cold air intake", but you can design a true "cold air intake" with the filter in the engine compartment.

 

[crossbow]

Aye Keith, I agree. Basically it sits over the wheel well, with some sort of plastic insulating shield around the engine compartment. Technically if you can keep the intake air at ambient, and shield it from engine heat...running the shortest intake pipe possible is usually the best course of action.