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Should you use a K&N "Air filter"?
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=65&t=19506		 Page 1 of 2
Author:  JJsTJ [ Tue Apr 10, 2007 9:24 am ]
Post subject:  Should you use a K&N "Air filter"?
Should I use a K&N Filter?

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"NO!!!

The K&N filter and other like it were originally designed for racing and to keep the air just clean enough to last the life of the engine which was generally one or two races between rebuilding. The one thing you always see on the filters of this type is there is a lot of sales hype and never any proof as to filtering abiity. K&N acutally states if I remember correctly 97% filtering ability, OEM is generally 98% to 99.5% and the difference between what that claimed 97% difference is and OEM is mind stagering in the amount of dirt past into the engine.

The real proof of the pudding was ISO testing on a GM Duramax Diesel and engine oil sampling from VW TDI diesels a couple years ago on TDI Club Forum. The increase of silicon (Si is dirt) in the oil was on the order of 5 to as much 10 fold increase over normal. That is 500% to 1000% increase of the dirt into the oil by the way.

One other point, people buy these for is to incrase HP output. Actual dyno testing on VW TDI diesels (VW's have same turbo as the CRD and is IC system) only showed HP increase of less then one hp for the diesel and a turbo gasser. On the speed channel one day they did a bunch of preformance mods on a new '05 V8 Mustang and after each mod they checked output on the dyno. The V8 picked up 8 hp for the K&N ram system, they acted a little embarresed but went on with other mods. I didn't think the K&N cone syatem used was a good return on the $300 cost."

(source: Old Navy post in CRD section)

I couldn't have said it better myself. :wink:
Author:  tommudd [ Tue Apr 10, 2007 5:08 pm ]
Post subject: 
YES is the answer, has worked fine for me on 4 different vehicles, but here we go again. It depends alot of where you live also, how and where you drive out west lots of blowing sand,

Oh never mind I like mine never paid $300 for any of mine and I have seen shows where they got more than 8 horsepower To each is own. I have to stop reading these things, becuse then I have to put in my three cents :wink:
Author:  jcphoto20 [ Tue Apr 10, 2007 8:41 pm ]
Post subject: 
NO is the answer used by informed, intelligent people that care about how much dirt is let into their intake tubes/throttle bodies/intake/cylinders.


YES is the answer used by those that are stubborn enough to believe they are actually getting any benefit other than increased noise, dirt, probability of oil contaminating intake electrical components.

The money savings argument is questionable due the afformentioned risk to expensive parts, the cost of filter cleaners and filter oil. Plus the fact that you will eventually have to clean the inside of your intake and are scratching your cylinder walls which will most certainly shorten your engine life, despite your denial.

The point about not living where the dust and sand is located is just ludicrous, there are small airborne damaging particles everywhere. Of course the amount is admittedly less, but its still there, and you obviously don't care about it.

You may conceivably gain a few horsepower on a highly restrictive intake, which the one on our jeeps is not. So you will gain no horsepower from a filter change, and negligible from an entire intake swap.
Author:  CaKJFreedom [ Tue Apr 10, 2007 8:44 pm ]
Post subject: 
I think the "intelligent" part wasn't needed.
Author:  jcphoto20 [ Tue Apr 10, 2007 8:52 pm ]
Post subject: 
you are right, you only need to be intelligent enough to understand the information that you were informed of.
Author:  tommudd [ Tue Apr 10, 2007 10:16 pm ]
Post subject: 
jcphoto20 I could say something but I am way too intelligent for you to even follow along as I find your response sort of kindergardenish. If you think that everyone on here wants to listen to someone who thinks they know everything well...... :wink: I like to get people riled up a bit, to think for themselves, to think outside of the box, to think on their own. But you of little knowledge only care to listen to one voice, the one in an empty head. Open up your mind grass hopper :lol: :lol: :lol: JJsKJ understands that I am sure lighten up and get off your imaginary high horse :wink: Now if you cant take the joke dont read anymore of my posts, been doing this a loooong time!

Tom
Author:  QuestMan [ Tue Apr 10, 2007 10:16 pm ]
Post subject: 
So.............The NEXT logical question would be, "If K&N filters are of questionable value, then is there an available high-flow filter which WOULD be recommended"?
Author:  tjkj2002 [ Tue Apr 10, 2007 10:23 pm ]
Post subject: 
QuestMan wrote:
So.............The NEXT logical question would be, "If K&N filters are of questionable value, then is there an available high-flow filter which WOULD be recommended"?
Well I've had very good luck with AEM's dryflow synthetic filters,washable but not that medical gauze like the K&N's.
Author:  tommudd [ Tue Apr 10, 2007 10:30 pm ]
Post subject: 
tjkj2002 how do you clean the AEMs I have looked at them but never talked to anyone who was running them. I am up for anything different , new that works better, but also not 300 bucks! :wink:
Author:  tjkj2002 [ Tue Apr 10, 2007 10:35 pm ]
Post subject: 
tommudd wrote:
tjkj2002 how do you clean the AEMs I have looked at them but never talked to anyone who was running them. I am up for anything different , new that works better, but also not 300 bucks! :wink:
They have a special cleaning solution but I just use good'ol Dawn dish soap,let air dry and reinstall.By the way I replaced my AFE oiled cone filter(just like the K&N) with a AEM dryflow.AEM has the brute force systems for the KJ's that come with the new dryflow filters.I have noticed no more dirt in my intake tube and cleaner oil at my oil changes for what it's worth.Also not saying the AEM's are better but they are(so far) a better choice to a K&N as far as reusable filters in my opinion.
Author:  Site Admin [ Tue Apr 10, 2007 10:37 pm ]
Post subject: 
CaKJFreedom wrote:
I think the "intelligent" part wasn't needed.


I agree.
Author:  tommudd [ Tue Apr 10, 2007 11:10 pm ]
Post subject: 
tjkj2002, I know some get an oily residue in the intake but with over 75000 on mine with the K&N on since 5000 miles I have never had anything show up. But ,....wheres the best place to buy a AEM and what size are you using? Have to do some looking this weekend

Tom
Author:  JJsTJ [ Tue Apr 10, 2007 11:25 pm ]
Post subject: 
The AEM are pretty good filters but I really like..... Insert Amsoil ad here>
Amsoils new Ae series air filters. Sure they don't currently offer all the drop in filters yet but they do offfer a nice variety of cone versions and the old-school round hot rod style filters. They are a dry media filter that filters at a high efficiency rate and do not use oils or special cleaners. They can be blown clean w/ compressed air or vacuumed.

I recently ordered a cone version to replace my FIPK filter (KJ came w/ it, I wouldn't have spent the money on it myself) and I will get more info on that when it arrives.
Author:  csukoh78 [ Tue Apr 10, 2007 11:47 pm ]
Post subject:  Whoa there horsey...
One thing that is ALWAYS neglected in conversations like these is that in all these tests, the K&N's they use are BRAND NEW. The oiled guaze medium is one of the few mediums that actually has an increase in filtering ability as it gets dirtier.

As small particles hit the oil and are trapped, they provide a richochet force to other particles before they get through, increasing the likelyhood that they too will get trapped. More particles=more richochet=even more trapped particles. The amount of particles trapped grows logarythmically. ( Same as exponential but includes a limiting factor of surface area)

Airflow does not suffer, because the richochet of the particles is done in-line at the same velocity until they are trapped, thus not reducing airspeed. (Think of a football tossed down a hallway, bouncing off walls but not slowing down much.)
That is why K&N's are fan shaped....it keeps the trapping medium nearly inline with the particle path while having the minimal impact on airflow. This is different than paper filter media or foam filters.

Particles trapped in oil can still move in the oil, therefore once trapped by the surface tension they take the path of least resistance until they settle elsewhere in the cotton, in a place that does not occlude airflow. Paper filters, on the other hand, have fibers which create inflexible pores. Once a particle is trapped in the pore, it cannot move, and the airpath of that area is permanently blocked.

Basically, when comparing paper and K&N brand new, the K&N is at a disadvantage, whereas the paper is at the top of its game. As time passes, paper gets worse, and K&N gets better.

Do that same test 10k miles later and you will see the difference. Its performance is dramatically improved.
Author:  JJsTJ [ Tue Apr 10, 2007 11:58 pm ]
Post subject: 
Oh cool, so my engine only ingests dirty air for the first 10,000 miles then not so much. I feel better already.

How about if I just use a filter that FILTERS from new and then clean it when it gets dirty and reinstall it? I AGREE that the K&N lets in more air and filters better when it gets dirty but I can't have that in the desert environment I live in. For on-track racing on an engine that sees regular rebuilding it is fine but I wouldn't use one around town in this dry, dusty town on a daily driver when there are better FILTERS that flow as good or better and actually filter the air.
Author:  csukoh78 [ Wed Apr 11, 2007 12:08 am ]
Post subject: 
JJsKJ wrote:
Oh cool, so my engine only ingests dirty air for the first 10,000 miles then not so much. I feel better already.

How about if I just use a filter that FILTERS from new and then clean it when it gets dirty and reinstall it? I AGREE that the K&N lets in more air and filters better when it gets dirty but I can't have that in the desert environment I live in. For on-track racing on an engine that sees regular rebuilding it is fine but I wouldn't use one around town in this dry, dusty town on a daily driver when there are better FILTERS that flow as good or better and actually filter the air.


No one said you have to, and besides, that is not what I said. I never suggested that it *suddenly* works at 10k miles. I merely point out that the two have different properties, and should be picked as such. Any severely dusty environment would benefit from disposables, whereas almost anyone else could use either just fine.

Also, any data K&N releases obviously has to be with a new filter, thus the 97% as opposed to 98%-99% of a paper. But, later on, the K&N will save you some money, and its easy. Just clean it every 50k miles and you are golden. Don't forget you have an oil filter to help out with ALL that extra dirt you think you will inhale.
Author:  jcphoto20 [ Wed Apr 11, 2007 1:46 am ]
Post subject: 
i stand by my post. i know what im talking about.
Author:  tjkj2002 [ Wed Apr 11, 2007 8:33 am ]
Post subject: 
tommudd wrote:
tjkj2002, I know some get an oily residue in the intake but with over 75000 on mine with the K&N on since 5000 miles I have never had anything show up. But ,....wheres the best place to buy a AEM and what size are you using? Have to do some looking this weekend

Tom
I bought mine at Advance Auto Parts,don't off hand remember the # but when you find a locall dealer just bring in your K&N and find one the same size as the K&N(at least the same size opening).JJ,since I was in a hurry so I went with AEM's filter,cause at the time I could not wait for a Amsoil filter.Amsoil filters are really good to.
Author:  JJsTJ [ Wed Apr 11, 2007 9:27 am ]
Post subject: 
tjkj2002 wrote:
tommudd wrote:
tjkj2002, I know some get an oily residue in the intake but with over 75000 on mine with the K&N on since 5000 miles I have never had anything show up. But ,....wheres the best place to buy a AEM and what size are you using? Have to do some looking this weekend

Tom
I bought mine at Advance Auto Parts,don't off hand remember the # but when you find a locall dealer just bring in your K&N and find one the same size as the K&N(at least the same size opening).JJ,since I was in a hurry so I went with AEM's filter,cause at the time I could not wait for a Amsoil filter.Amsoil filters are really good to.


No worries. :D
Author:  KY Liberty [ Wed Apr 11, 2007 1:43 pm ]
Post subject: 
I've had the K&N for about 55k miles with no problems. Around 25k of that has been with the ram air. The oil usually only causes problems with vehicles such as Fords with a mass air sensor. It actually says not to use them in their manuals. Also, the closest mine comes to off roading is an occassional gravel road, and some snowy mountain roads. I have to rotate the cone at 1500 miles, and clean it at 3000 miles with each oil change because of the hood. The top side of the cone is almost black after 1500-2000 miles with all that air being dumped into it. There is a drop in on both my parent's 98 Cherokee, and 2003 Grand Cherokee. Neither of them has ever had a problem with them either. I am considering going to the dry AEM though since I can no longer get my cone very clean. I'm sure it doesn't breath as well as it used to, but it probably filters a little better.
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