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Discussion Starter · #1 ·
For those of you who want to know how much dirt a K&N filter lets by and how much of a difference the foam wrap makes on you K&N filter...here you go...take a look at silicon levels before and after, it drastically dropped silicon (dirt) to a level I can deal with in the sample and in turn all wear metals dropped significantly as well, the high lead is from a couple tanks of race gas. So for all you guys that think a K&N filters well here is the proof. Just thought I would share it with you guys.
 

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I'm only phone and having trouble comparing. How did you perform these tests? What's the variables?
 

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Discussion Starter · #3 ·
Samples were taken at oil change and sent to blackstone for spectrometric analysis, although I am not sure where the center colum numbers are from the far right are universal averages, the first colum is my most recent sample with 6 hrs on the oil with the foam wrap, the third colum is 12hrs on the oil with just the K&N no foam wrap.
 

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Whats a foam wrap on a k&n ?
 

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Chainsaw: It's a type of outterwear. (prefilter)

Rappy, What type of terrain are you riding?
 

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Discussion Starter · #6 ·
I ride in dusty/sandy areas.
 

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ive never had luck with K&N, always failed the "wipe inside the intake tube" test with a finger full of dirt/dust.

uni foam stock style filters have always done the best for me.
 

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Chainsaw: It's a type of outterwear. (prefilter)

Rappy, What type of terrain are you riding?
I no what a prefilter is but its not foam . Is there a prefilter made outta foam ? Is he just talkin about a regular k&n prefilter ? I've never seen the foam one.
 

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It is a regular K&N prefilter is all, like the black mesh. There would be no point of running a foam w/ the K&N, I actually don't think it is possible.
 

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Discussion Starter · #11 ·
What I did was take the outer foam layer off an old uni filter and run it over the outside of the K&N, and if you don't think there is a point of running one with a K&N then you did not look at the sample results I posted....but it's your motor.
 

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There would be no point of running a foam w/ the K&N, I actually don't think it is possible.
K&N actually makes foam filter wraps for certain filters.

http://www.knfilters.com/airforcewraps.htm

I used to run one on my old Toyota truck. I have wanted to buy one for the K&N on my current truck, just have not got around to it yet. A bunch of guys who race in the desert run them on their trucks/buggies, pretty common actually.

My only comment on the test is you ran for 6 hours with the wrap, then 12 hours without. Test showed more dirt in the oil after running with no wrap. Wouldn't it stand to reason that you ran twice as long in dusty conditions you would have more dust by the filter into the oil? I am sure if you ran with the wrap for 12 hours, you would have more dirt in the oil then the 6 hour test. Probably still not as much as the no wrap test, but the difference could be less if the run times were the same. I may be buying a foam wrap for my truck sooner then I thought!

Doug
 

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Discussion Starter · #17 ·
Your theroy on the run time difference would be sound if the level had only dropped in half, which it dropped much more than that, or we could argue that it was dustier on the run of 12 hrs, whatever...the bottom line is this, in order to get performance from your filter (more flow) you WILL sacrifice its ability to filter the air, so I guess the question you need to ask yourself is how much is too much sacrifice, if you have no problem with liquid sandpaper running through you engine, by all means continue to use you K&N filter and tell yourself that it filters fine and I have never had a problem with it, my throttle body is always clean...its your motor, I posted this to show people that K&N filters DO let an unacceptable amount of dirt through your filter and a means to protect your motor, you may choose to use this info or not, it is up to you, I for one have way too much invested to prematurely wear things out to obtain an extra 1 or 2 HP.
 

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Discussion Starter · #18 ·
Scuzz, I removed the outerware and replaced it with the foam wrap, but I guess you could both if you wanted too.
 

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Your theroy on the run time difference would be sound if the level had only dropped in half, which it dropped much more than that, or we could argue that it was dustier on the run of 12 hrs, whatever...the bottom line is this, in order to get performance from your filter (more flow) you WILL sacrifice its ability to filter the air, so I guess the question you need to ask yourself is how much is too much sacrifice, if you have no problem with liquid sandpaper running through you engine, by all means continue to use you K&N filter and tell yourself that it filters fine and I have never had a problem with it, my throttle body is always clean...its your motor, I posted this to show people that K&N filters DO let an unacceptable amount of dirt through your filter and a means to protect your motor, you may choose to use this info or not, it is up to you, I for one have way too much invested to prematurely wear things out to obtain an extra 1 or 2 HP.
Thanks for the useful information , I was using a Uni Filter with outerwear and the inside of the filter is dusty. Maybe I need to try something differant. :D
 

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Hey Bax, what uni setup? Does it have both the yellow and the red foams?
 
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