Does K n N air filter really work?

I've purchased two cars in the past upon which the POs had installed K&Ns: A 400HP Jaguar XKR and a 300+HP Modified Roadmaster Station Wagon (it was a wicked car - lol). In both cases I removed the filters as soon as I was aware of them. I wasn't going to expose either a Supercharged Jaguar or LT1 engine to the extra grit the K&Ns let through. I typically keep my cars for a very, very long time (100K+ miles), so the minuscule extra horsepower isn't worth the risk to engines' longevity. I'd never even consider installing them in the 360, nor any possible future 430/458. I take care of my engines.

 

+1

Of the two stronger OPINIONs put forwarded one Op was in Sales and the other an Employee.
Think they might be biased?

One of them even insulted all the Engineers owners (me included) with,

This is turning out to be a funny thread.

 

who started this nonsense that a K&N lets more dirt in an engine ? NOT true ! maybe if not oiled ! we have used them in the desert for many years !
whoever is spouting such nonsense does not understand air filter engineering / construction ( and they are wrong )

K&N air filters collect and trap particulate matter in a manner very different from disposable filters. A paper filter exhibits a principle called “surface loading”—dust collects only on the surface of the media. In contrast, K&N filters utilize “depth loading”, in which multiple layers of cotton fibers provide particle retention on multiple levels, and the media also features pleats to increase surface area over disposable filters. As a result, K&N filters are able to hold significantly more dirt and particulate matter per square inch of media over an average paper filter.provide a high level of airflow while simultaneously targeting an overall filtration efficiency of 98%.( NO filter is 100% ! )

 

point is people stating opinions instead of doing even basic research ! noone insulting, nor demeaning engineers ! ( not myself anyway ! ) I am quoting engineers !
Certainly NOT making an Ad homenin argument ! thank you !
IME when that nonsense starts, the discussion is no longer rational , nor fair .
I have no bias, am not an K&N employee and have done research ,other than quoting opinions and anecdotal experiences found in other forums ! .
I am only biased in the way that I have used the filters and found NO fault w/ them or their performance .

 

IME your assumption that K&N let in more dirt is wrong May I ask ,where did you get proof of that ?


K&N air filters collect and trap particulate matter in a manner very different from disposable filters. A paper filter exhibits a principle called “surface loading”—dust collects only on the surface of the media. In contrast, K&N filters utilize “depth loading”, in which multiple layers of cotton fibers provide particle retention on multiple levels, and the media also features pleats to increase surface area over disposable filters. As a result, K&N filters are able to hold significantly more dirt and particulate matter per square inch of media over an average paper filter.provide a high level of airflow while simultaneously targeting an overall filtration efficiency of 98%.( NO filter is 100% ! )

 

yes i believe it is true they do have an extensive R&d department and have been making filters for a LONG time ! they do have dyno proof as well at least for some applications , most / many racers use K &N .

 

Most of the K&n air filter kits they market do not have the filter breathing in hot engine air ! modern design is followed and most kits have a filter in the stock airbox or offer a new box and cool air intake
I have seen DIY installations / installers do that though

 

I have used K&n for many years in all kinds of vehicles and NEVER seen that !

 

UH, we have used K&n in many different vehicles including in off-road use and NEVER seen dirt downstream of the filter ! did you have a loose clamp ?
that could do it . IF this was REALLY an issue there would be MANY reports and I have NEVER seen any until reading it here !

 

thank you ! and i agree 100% we have used K&N for years w/ NO ill effects and seen gains in power ! i noticed a gain in my F430 I would say 5-15 HP which correlates w/ others experiences and is a reasonable claim .
some tests I read have said a brand new paper filter may even flow as much ( or nearly as much , depending on the application )They, paper ,sadly do NOT stay NEW but they quickly get dirty and then flow MUCH less

 

Maybe because the paper filter (OE) is filtering more particles while the K&N is allowing more to go through?
So yes, you loose the power gain by less filtration but keep your intake tract cleaner.

My car has more power than I can handle and so I prefer to keep my engine internals cleaner and stick with the 400 horses.

 

NO,the problem again is you assume the K&N allows MORE dirt in and that is just factually incorrect ! Where IS the proof ! ?? K&N they have a 98% efficiency! no filter is 100% !
the difference is in the design ! the K &N pleated cotton has a Labrinth of fibers the dirt has to get thru a virtual MAZE and the oil traps a LOT too !

 

Just to be clear, some facts (not opinion)

1. I have personally dyno tested 360, 430, 458 and 550 cars with stock, no air filter and pleated gauze air filters. On ALL of these cars, gains are found with no filter and with the gauze filter.

2. I have 35K miles on pleated gauze filters on our 1999 550 Maranello living in SoCal and Arizona with no issues of oil or dirt/residue past the filter.

3. I have personally seen the testing that companies like K&N, BMC and some others do. Having worked in that industry, I was privy to seeing much more than the average consumer.

4. I was chief instructor at a Ferrari school at WIllow Springs (one of the dirtiest and dustiest tracks in SoCal (maybe the USA)). I have seen more than 1 (meaning 100's) of cars with pleated gauze filters come and go without issue. (Yes, that is me in the '55 car that Scaglietti competed with in the Casablanca GP)

I do NOT sell automotive parts nor do I work for any of these companies any longer. I have ZERO bias, in fact, I had a significant falling out with K&N and would love to be able to bash their product as I have a distaste for some in the C-Suite (whom I reported directly to). If anything I have a bias against them! lol. But the truth is the truth and I cannot stand "engineers" whom have no personal experience and just recite internet lore as fact and say "but i'm an engineer - you have to believe me!"

When I managed automotive motorsports engineers (both on the tuning/aftermarket/club-racing side as well as a team that kept NASCAR and INDY car engines running), they would listen to anyone with facts, even if they were "sales" people! lol I ran 2 divisions of Cosworth (you may know them, you know F1, initial Singer Engine builder, Factory electronics to the Porsche motorsport cars, INDY and NASCAR electronics supplier, etc.) we significantly tested filters. And you know what, we used pleated gauze quite a bit. But what does a company like Cosworth know? lol

Again, opinion is awesome. It is also wise to actually listen to people who have facts and experience that may be more than just opinion. I spent 30 years in the automotive aftermarket and motorsport world running companies, race teams and major divisions. Primarily focused on the major European makes, with significant Ferrari exposure. I have a little bit of real world experience here. But "oh well" - I am just a "sales" guy as someone put! lol

Just somethin' to think about!

 

Your bona fides and resume seem pretty impressive to me ! and I'm convinced !
I think K&n are great I use them , have for years w/ NO ill effects and gained HP and torque
guys on forums typically/ frequently take cheap potshots and use ad hominem arguments to try to "win " an argument !
Or GASP ! even make things up !
They note effects most people NEVER experience , or have NEVER reported ! Hey ! your anecdotal experiences may be valid but your data may be an outlier ( or are you just a liar ? )
It's sad ! and some are intellectually dishonest
they were never on the old high school debate team I'll bet !

 

What about K&N website ( https://www.knfilters.com/efficiency_testing.htm ) ?

The ISO 5011 they are using is the standard testing procedure. So Based on their own data K&N filtering efficiency can be as low as 96%. What they do not say in this page is that any cheap paper filter is -well- above 99%. This is significant as a 96% efficient filter will let pass 8 times more dust than a 99.5% efficient filter.

As a side note there was an interesting paper on "dust loading". To make a long story short: once they have swallowed 100mg~200mg of dust, all filters are equally restrictive. So unless you clean K&N very often, you quickly loose the additional flow. https://moto.lexp.net/wiki/ISO_5011_Duramax_Air_Filter_Test_Report

Here again, my point is not to pretend these are bad products (they are well made for sure), but let's not expect magic HPs from these filters, and whatever edge you have will be lost after 500km (your mileage may vary...). As a prospective buyer I'd rather buy a car that was regularly serviced with factory UFI / MANN / Baldwin filters.


PS: quite a lot of passion and bias (me included) in this thread...

 

Pore size on K&Ns is microns larger than quality paper filters (and even with pleats, K&Ns typically have less surface area). Unless you're using electrostatics or centrifugals to "attract/discharge" particles, bigger holes mean larger (and more) particles will get through. The comparison photos from Bobstheoilguy really should end the questioning. Sorry to disagree. Incidentally I "am" one of those proverbial Engineer Types (Aerospace), so I don't entirely speak from completely unfounded emotion/opinion.

 

++++++++++++++++++++++++++++++++


All I can say is wow. You joined this group in 2021 for what purpose?

Why am I here? I am here because although I am intellectually capable of working as an Engineer in a nuke plant for close to 40 years (I retired and returned as a Consultant) with all of its technologies yet when it came to my cars (old Porsche and 360) I was incapable of maintaining them without the dealers.

Tech Spec/Facts/Engineering: Most parts for my 928 are Factory NLA. Many of the procedures to maintain, replace or repair parts are based on the experiences of others. Without my Rennlist friends I would not have been able to maintain it. In a similar fashion here at FChat I have learned the same; how to do a proper coolant drain/refill and vent. How to repair broken parts or to correct OE related issues such as exhaust hangers, leaking cam covers to name a few. Trev360 has even figured the IMMO system as well as the ECUs well enough to manipulate its functions to suit our needs; my needs. Most are incorporated in my car. When you are unable to get into one of your doors the folks here will teach you how to get in and repair/replace the cable. This group is an invaluable asset to own a 360/430. Collectively, we learn from each other’s experiences i.e., those who have btdt.

So why are you here if you’re not going to listen or need the experiences of others?
What are you going to do when your F1 goes into N at a stoplight? Or you can't get it to start after you just drove it. Are you then going to come here and ask, “here guys anyone ever had this happen? What should I check? I read somewhere about the brake switch". Or are you going to have it towed to the dealer every time?

If you’re here to learn more about maintaining your car from some who are almost experts here then you have one hell of a way to show that you do.

Nuff said! I’m out!

 

your math is fuzzy 8X as much dirt ? No their website says :
"Our actual air filters when tested generally demonstrate a cumulative filtration efficiency of between 96% and 99%. All this testing we do allows us to guarantee our air filters provide all the protection your vehicle will ever need."
you are taking figures and facts out of context !
As for the other test you quoted ? https://moto.lexp.net/wiki/ISO_5011_Duramax_Air_Filter_Test_Report
They did NOT test K &N ! LOL
K&N DO work differently ! the oiled cotton gauze creates a labyrinth of layers A ,MAZE that dirt must wind it's way thru ! IN the process? nearly all dirt is indeed caught .
many millions use K&N all over the world ! noone finds any serious fault w/ them ! and IF they did not do great job ? noone would buy them !
We started using them in M/c's in the 1960's !
As per K &N,

"In 1964 Ken Johnson and Norm McDonald started a business for motorcycle enthusiasts. They rented and sold motorcycles and accessories to die-hard performance lovers. Soon the founders began answering various needs with high quality parts. One of those needs was for an air filter that could keep the fine dirt experienced in off-road racing from damaging the engines. This filter had to be washable and reusable and allow enough air to keep the motorcycles running at peak performance. The original K&N High Flow air filter was born and in 1969 K&N Engineering became known more for its performance air filters than for rental bikes and parts. It wasn't long before the filter technology was applied to automotive applications.

Fifty Two years later, Ken and Norm have moved on but K&N's commitment to providing top quality products that deliver as promised is stronger than ever. K&N boasts in excess of 55,000 applications, covering a vast majority of the vehicles on the road today. More than 800 employees research, develop and manufacture K&N products.

Headquartered where they started, in Riverside, California, K&N Engineering manufactures the majority of its products from raw materials on machines designed in-house. In addition to manufacturing, K&N has one of the most sophisticated Research and Development facilities in the performance aftermarket, complete with air filtration testing capabilities, engine and chassis dynos, air flow testing stations, mass air flow (MAF) meter testing and a myriad of other technologies to help K&N design and manufacture the best products possible.

K&N also has a manufacturing facility in the United Kingdom that covers Scandinavia, Russia, the Middle East and the European markets. K&N's distribution centers are located in Riverside, Warrington, and Venlo. To further internationalize, in 2000 a Sales and Marketing office was established in Eindhoven, the Netherlands and further expansion will continue into the future.

In its 52 years, K&N has continued to be a pioneer with numerous improvements to its products. In addition to their washable/reusable High Flow Air Filters, K&N offers four lines of High Flow Intake Kits that provide guaranteed horspower. K&N started a revolution with their Fuel Injection Performance Kits and AirCharger Kits, easy to install kits that replace the restrictive factory intake tract and allow a smooth flow of air from the company's famous washable and reusable air filter (all Fuel Injection Performance Kits are approved for use on Emission-controlled vehicles and 50 state legal). Today it's hard to find a performance vehicle without some form of intake system upgrade. When enthusiasts began asking for ways to improve the looks of their engine compartment and add performance, K&N answered with their Typhoon Intake Kits (69 Series) for sport compact cars and recently with their 77 Series High Flow Intakes for sport trucks - both offer high quality aluminum tubing (in polished or powdercoated finish) and premium hardware, along with a K&N air filter, for great performance and cool looks.

K&N Air Filters and Intake Kits are backed by the famous K&N Million Mile Limited Warranty™ -- K&N stands behind their products and more than 52 years in business shows that the company continues to satisfy its customers. K&N has garnered numerous awards from SEMA, including "Manufacturer of the Year in 1994, 1996, 1997, and 2000 making K&N the first company to receive this prestigious award four times.

Often imitated, K&N has yet to be duplicated and with a commitment to excellence, innovation and relentless drive to maintain their leadership position as manufacturers of the "World's Best Performance Air Filter," it's unlikely that any company will come close."

 

I think you are ignoring the multiple layers ! the surface area and the maze, the labyrinth the dirt has to go thru does a great job!
NO sorry i do not think "bobs the oil guy " has credence over the K&N engineers ! LOL is that "confirmation bias " you are showing ?
they told us in academia to defer to the senior researcher ! BOB is outranked ! Or as they say in UK ? "bobs your uncle "LOL
Image Unavailable, Please Login

Image Unavailable, Please Login

Image Unavailable, Please Login

Image Unavailable, Please Login

View all
"Bob's your uncle" is a phrase commonly used in Ireland, the United Kingdom and Commonwealth countries that means "and there it is" or "and there you have it" or "It's done". ... Typically, someone says it to conclude a set of simple instructions or when a result is reached.



and our family has used these filters since the 1960's when they first were sold for M/C's

I have wondered IF we could add some electrostatic wires to a filter as my home filter does ! It has an electrified grid built into the weave ! does a great job w/ pollen !

 

I've been running K&N's (x2) on my F355 for over a year.

Additional HP? Dunno, perhaps. I don't wring it's neck and any additional gains are likely not felt anyway.

Any issues? None. Better sound from the airbox? Yes.

I run them on all my motorcycles (x3) and have done so for the last 10 years.

Do I "like" them, yes. But I'm old school.

Would I re-use them? No. I just buy new ones.

Does it really matter? Probably not.

Just my experience.

This is like just another oil thread.

 

well, bit a ad hominem argument there eh ?
I am here to learn and share and contribute NO we will not always agree! why should I IF I have good reason to disagree ? WE listen , don't expect us to obey ! our history prepared us well to do so ( Disagree ! )
some things are really NOT debatable and some things are . If someone suggests a way to fix something I would probably find a second source if there was any doubt ! otherwise in many cases there is NO argument, or differing rationale or possible other way to do it ! WE feel a great responsibility to be a careful caretaker of our car so it is preserved for the NEXT owner ( if any ? ) our mechanical work is precise and complete and we use only the best parts as possible, practicable.
Anyone who ends up w. one of my vehicles is lucky ! it's right ! I have a wealth of knowledge to draw upon in my family ! techs , racers, engineers .

 

yes but worse ! at least there is PROOF re oil !
Blackstone oil analysis
engineers say it makes virtually NO difference in engine WEAR what brand of modern synthetic oil you use !
as ALL oil has to meet min SAE stds ( and does )
so w/ in reason , use what you like ! as long as the weight , EG 5W40 is as spec'd by the OEM

 

Anybody here change their mind one way or the other?

 

I'm not sure how our verbose friend Jan can pretend this isn't real - I was around on the Miata forum back when this was tested (PROPERLY), and it's impossible to dispute that more dirt was passing through the K&N and being captured by the secondary filter than was passing through the other filters. Simple, visual proof, not conjecture. Nobody cares if the gauze structure has layers full of big holes, the dirt captured after it passed through the filter blows bigger holes in the theory that dirt can't find it's way through the layers.

Anybody who says they've never seen or heard of dusty intakes behind K&N filters has led a very sheltered life - it's a common complaint expresses frequently all over enthusiast car forums. You might want to upgrade your Google search skills and try again, you'll find no end of those complaints.

As I said before - K&N has very good marketing writers and lawyers who make sure their ad copy is very carefully worded. Jan posted the perfect example:

Do they claim to filter better than, even as well as, paper filters or competitor filters? No! They claim, even guarantee, that "our air filters (will) provide all the protection your vehicle will ever need." I have lots of experience in my engineering career with deciphering and interpreting this sort of legal weaseling, and the K&N guys are GOOD. Imagine how you could ever challenge that claim in court? It's pure nonsense, defined specifically to be so vague as to be meaningless. Marketing nonsense.

Gordon

 

Well this does remind me of the silly you tube videos where guys like " Clem" ,claim a Fram filter is defective and will and has failed !
pure balderdash . they will cut one apart and point to certain things . In reality, there is nothing wrong w/ Fram filters and IME there is nothing wrong w/ K&N filters we have used them for many years and so have millions of others .
clearly, you will not be convinced, swayed I wouldn't try . You have invincible stubbornness. use whatever you like ! So will I !

PS I have MUCH more faith in our esteemed lawyers than you . people get sued for anything and everything here in the USA . Lots of hungry litigators they are a layer of consumer protection not available in Europe! and ROW .
Just like Fram Filters , IF there was something wrong , defective about K&N filters ? there would be lawsuits and some would prevail IF they were defective Heck they might even prevail if they weren't defective!
This is a great book ! very useful in marriages too ! ( Hide it fr your spouse ! ) He was lawyer who "never lost a case " ? only .94 cents now ! ( used ) Image Unavailable, Please Login