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When I bought my 97 Ford Expedition I bought a K&N air filter for it. It has made a lot of difference in the performane of the engine.

 

I'm wondering ... does anyone know of any proven benefits of using a K&N on a Soob?

 

(Fiance has a 2000 Forester S w/ auto trans & 70k miles.)

 

AWD

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i've had good luck with K&N filters. i've had one on my XT6 at 220,000 miles. i got the car with 105,000 miles and installed the K&N early on. i also ran one on a previous XT6 which i had from 75,000 to 196,000 miles.

 

i emailed another board member about using them on a 1997 OBS and he said he used one with no problems and liked the results. he used the cone style, i use the drop in stock replacement.

 

i have no data on performance except to say i seem to recall (been awhile since i've had it in for over 100,000 miles) it pulling a little better over 3,000 rpms. if you're looking for power, this isn't the way to get it, you'll be disappointed.

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From what I've read, K&N's are not much higher-flowing versus paper filters, and they let in more wear particles than other filters. I give them a thumbs-down.

I agree totally. For the marginal if any performance gains they are not worth the wear. This is why HD Dodge and Chevy diesel engines void the warranty if you use them. Does not seam worth it to me.

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ive been using one on my impreza since i got it at 69k, im now at 122k and have absolutely no problems related to the cone filter. at least none that are worth remembering.

 

k&n is probably one of the best filters in the aftermarket, id definatly go use k&n or hks.

 

as for cone filters not improving performance, thats bull, when i added mine, my car was bone stock with a brand new paper filter. i noticed a definate difference in power and accelration. especially at high rpm. that and the sounds were cool too. the car instantly had better acceleration than stock, and thats just with a cone filter mounted to the throttle body. granted, that only works on map based engines, not on maf engines.

 

another car that benifited greatly from a cone filter was my friend's 1990 toyota camry with the 3s-fe inline 4 engine. afterthe filter was put in, his car would actually accelerate like a real car. and top end was much improved.

 

you can bash aftermarket intakes all you want, but ill never go back to stock intakes, both of my cars have cones in em.

 

 

peace

tim c.

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I am not disagreeing that there are performance gains with these filters. But what do you get 5-10 hp max? I run my cars to 200k and the additional particulates these filters allowing into the system, especially if you live in dusty or dirty road are not worth it for me personally. I am sure if you run these in urban only areas you could be fine but for me I drive a lot of dirt roads and we put sand down on the roads in winters so it is not worth the risk to me.

 

 

 

ive been using one on my impreza since i got it at 69k, im now at 122k and have absolutely no problems related to the cone filter. at least none that are worth remembering.

 

k&n is probably one of the best filters in the aftermarket, id definatly go use k&n or hks.

 

as for cone filters not improving performance, thats bull, when i added mine, my car was bone stock with a brand new paper filter. i noticed a definate difference in power and accelration. especially at high rpm. that and the sounds were cool too. the car instantly had better acceleration than stock, and thats just with a cone filter mounted to the throttle body. granted, that only works on map based engines, not on maf engines.

 

another car that benifited greatly from a cone filter was my friend's 1990 toyota camry with the 3s-fe inline 4 engine. afterthe filter was put in, his car would actually accelerate like a real car. and top end was much improved.

 

you can bash aftermarket intakes all you want, but ill never go back to stock intakes, both of my cars have cones in em.

 

 

peace

tim c.

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i drive a lot of gravel roads and back country roads around here, as well as a lot of highway driving. they also put down sand as well as calcium and salt during winter here. sofar, in nearly 50-60k using the k&n cone filter, ive had no issues with the filter letting in particulates that cause any issues.the only notworthy problem that i can remember, is that one time when on the high way while following a semi truck in a heavy downpoor, there was so much water getting to the filter that the car started to sputter a little bit, granted, it was raining so hard that i sholdnt have been trying to drive that day..

 

 

 

i still say that if you take care of the filter, clean and reoil it properly and when needed, you wnt have any problems.

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K&N Filters do just fine with filtering out particles large enough to cause engine damage. I have one on my car and my wife's car and neither of us has had a problem. I've been using their filters for over 5 years now and never had a problem. Check out their website about how well they filter. There are independant tests that prove they filter just fine.

 

http://knfilters.com/facts.htm#word

 

If you can prove that these filters do not filter and can cause engine damage, post it. And I'm talking proof that the filters fail or do not work. Not because some kid bought a kit off ebay and didn't install it right. Personally, I don't think such proof exists.

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Depends on your point of view.

 

You can find hundreds of sites that state damage caused by them. I have not dog in this fight; I am just stating how I do not think 5hp gain is worth the possible damage and dirt/dust allowed into the oil system of the vehicle.

 

 

 

 

Here are a few quotes from sites:

 

 

A scientific test was done on TEST filters where air was loaded with ACCTD (some standardized "test dust" called AC Coarse Test Dust) and sucked through the TEST filter then through an analysis membrane. From the Quantity of dust injected and the amount that gets through the TEST filter and is then captured on the analysis membrane we can calculate the efficiency of the TEST filter in Question.

 

 

BMW Stock Filter, Eff. Area of Media: 8.4 sq ft.

K&N Replacement, Eff. Area of Media: 1.6 sq ft.

 

The filters are the SAME size. They both fit in the STOCK BMW M3 airbox. The difference is that the STOCK filter has 65 pleats 1.5" deep and the K&N only 29 pleats each 0.75" deep.

 

Now, remember this ratio: " 5.25:1". It's the ratio of the AREA of STOCK to K&N. It's very important and will come into play later.

 

 

The STOCK filter efficiency started at 93.4% at 0 loading and increased to 99.2% efficiency as the loading increased to a max tested of 38.8 gm/sq ft of dust.

 

 

The K&N filter efficiency started at 85.2% at 0 loading and increased to 98.1% at the max tested loading of 41.38 gm/sq ft.

 

 

Now, I hear you. "Jim, that's only a FEW PERCENT". But is it?

 

 

Let's look. If we had 100 grams of dust on a new BMW filter we would let through a total of 6.6 grams of dust in. If we used the new K&N filter we get 14.8 grams of dust. That's 224% (TWO HUNDRED TWENTY FOUR PERCENT!!) more dust ingested initially, stock vs. "free flow" and this ratio is pretty much held. Somewhere between 200-300% more dirt gets "ingested" anywhere across loading equivalence. The more INTERESTING thing is when you look at what happens to the DP or Differential Pressure at a constant airflow as you dirty both filters equally with time.

 

 

The test used a rate of 75gr of dust per 20 min. Here's where the AREA difference comes MAJORLY into play. See, even though the BMW filter flows a bit less at the SAME loading, it also LOADS UP 5.25 times SLOWER due to it's LARGER effective area. So what happens is that the K&N initially flows better, but as the dirt continues coming in, the K&N eventually flows WORSE while still letting MORE dirt in.

 

 

Now, does any of this additional dirt cause problems? I dunno. I suppose we could have a few people do some independent oil analyses on different motors using both K&Ns and Stock filters. Get enough of them, and you'd have a good statistical basis. For me though, it's simple: More DIRT = BAD.

 

 

 

Another Example:

 

 

I was responsible for evaluating re-usable air filters for a major construction/mining company that had hundreds of vehicles ranging from large earthmovers to pick-up trucks and salesmen's cars. This study was embarked upon due to the fact that we were spending upwards of $30,000 a MONTH on paper air filters. Using them one time then throwing them away.. I inititated the study in that I was convinced that a K&N type filter or oiled foam would save us many dollars per year in filter savings, man hour savings, and of course engines as these would filter dirt better than paper. (yes, I had read the K&N ads and was a believer)

 

Representative test units were chosen to give us a broad spectrum from cars right through large front end loaders. With each unit we had a long history of oil analysis records so that changes would be trackable. Unfortunately, for me, every single unit having alternative re-usable air cleaners showed an immediate large jump in silicon (dirt) levels with corresponding major increases in wear metals. In one extreme case, a unit with a primary and secondary air cleaner, the secondary (small paper element) clogged before even one day's test run could be completed. This particular unit had a Cummins V-12 engine that had paper/paper one one bank and K&N/paper on the other bank; two completely independent induction systems. The conditions were EXACTLY duplicated for each bank yet the K&N allowed so much dirt to pass through that the small filter became clogged before lunch. The same outcome occured with oiled foams on this unit.

 

We discontinued the tests on the large pieces almost immediately but continued with service trucks, formen's vehicles, and my own company car. Analysis results continued showing markedly increased wear rates for all the vehicles, mine included.

 

Test concluded, switched back to paper/glass and all vehicles showed reduction back to near original levels of both wear metals and dirt. I continued with the K&N on my company car out of stubborness and at 85,000 miles the Chevy 305 V-8 wheezed its last breath. The top end was sanded badly; bottom end was just fine. End of test. I must stress that EVERYONE involved in this test was hoping that alternative filters would work as everyone was sick about pulling out a perfectly good $85 air cleaner and throwing 4 of them away each week per machine...

 

So, I strongly suggest that depending upon an individual's long term plan for their vehicles they simply run an oil analysis at least once to see that the K&N or whatever alternative air filter is indeed working IN THAT APPLICATION... It depends on a person's priorities. If you want performance then indeed the K&N is the way to go but at what cost???

 

 

 

K&N Filters do just fine with filtering out particles large enough to cause engine damage. I have one on my car and my wife's car and neither of us has had a problem. I've been using their filters for over 5 years now and never had a problem. Check out their website about how well they filter. There are independant tests that prove they filter just fine.

 

http://knfilters.com/facts.htm#word

 

If you can prove that these filters do not filter and can cause engine damage, post it. And I'm talking proof that the filters fail or do not work. Not because some kid bought a kit off ebay and didn't install it right. Personally, I don't think such proof exists.

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