cleaning K&N
10-01-2007, 02:45 PM
#2
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'06 E55, '05 SLK55, a few others
Probably not unless you see a lot dusty conditions. Just be sure to use K&N cleaner. Anything else can destroy the gauze and let dirt pass through. DO NOT get in a hurry and attemp to "blow out" the water!! Air dry only. Careful not to over oil as well. The people who have trouble with these filters don't follow instructions and then blame the filter.
10-01-2007, 03:22 PM
#3
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Probably not unless you see a lot dusty conditions. Just be sure to use K&N cleaner. Anything else can destroy the gauze and let dirt pass through. DO NOT get in a hurry and attemp to "blow out" the water!! Air dry only. Careful not to over oil as well. The people who have trouble with these filters don't follow instructions and then blame the filter.
Your spot on about the drying and oiling
On a side note, it takes the whole bottle of cleaner, and just a TINY bit of oil. I still have an oil can from about 10 years ago, and have cleaned MANY filters. If you have less than 25,000 miles you are probably wasting your time, unless you drive through ALOT of construction sites
See yeah
10-01-2007, 03:51 PM
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'03 E55
I thought that it was too early to really clean mine as well, but there was a very noticeable difference in my car after cleaning them properly. I have not re-dynoed my car after cleaning them, but the car seemed very sluggish before and that has gone away completely.
BTW - Thanks to Vadim for the advice to clean the filters.
BTW - Thanks to Vadim for the advice to clean the filters.
10-01-2007, 04:03 PM
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211 E55(sold) & 80cc shifter kart
please inspect your filter very closely, me and other members on here have had the k&n's start comming apart. the wire mesh starts to break apart, and little pieces of the mesh get sucked in! any way just a heads up to ya.
10-01-2007, 05:46 PM
#6
A well-respected BMW tuner had K&N filters tested by an independent lab a few years ago. The report was as follows:
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
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.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.<<
Others that have had their used oil analyzed report much higher levels of contamination when K&N filters are used. These disadvantages apply equally to all of the low restriction filters (green, bmc, etc.), so it's hard to justify using any of them for daily driving. Clean engine = happy, long-lasting engine. Your stock paper filter works great and really doesn't need a "mod" or an "upgrade."
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
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.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.<<
Others that have had their used oil analyzed report much higher levels of contamination when K&N filters are used. These disadvantages apply equally to all of the low restriction filters (green, bmc, etc.), so it's hard to justify using any of them for daily driving. Clean engine = happy, long-lasting engine. Your stock paper filter works great and really doesn't need a "mod" or an "upgrade."
10-01-2007, 08:15 PM
#7
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Thread Starter
A well-respected BMW tuner had K&N filters tested by an independent lab a few years ago. The report was as follows:
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark")... etc. "
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark")... etc. "
Wait, you're saying I should have bought a BMW filter ? Do they fit our stock airboxes ?
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10-01-2007, 08:26 PM
#8
10-01-2007, 08:55 PM
#9
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10-02-2007, 09:48 AM
#10
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'06 E55, '05 SLK55, a few others
A well-respected BMW tuner had K&N filters tested by an independent lab a few years ago. The report was as follows:
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
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.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.<<
Others that have had their used oil analyzed report much higher levels of contamination when K&N filters are used. These disadvantages apply equally to all of the low restriction filters (green, bmc, etc.), so it's hard to justify using any of them for daily driving. Clean engine = happy, long-lasting engine. Your stock paper filter works great and really doesn't need a "mod" or an "upgrade."
>>This was a scientific test, not one done by filter manufacturer X to show that their filters are better than manufacturer Y. The test results are pretty irrefutable as the test lab tests and designs filters where "screw ups" are absolutely NOT allowable (I can't say any more for security. Think "Glow in the Dark").
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.
The additional short-term airflow might make sense on a track car. IMHO, it doesn't for the street.<<
Others that have had their used oil analyzed report much higher levels of contamination when K&N filters are used. These disadvantages apply equally to all of the low restriction filters (green, bmc, etc.), so it's hard to justify using any of them for daily driving. Clean engine = happy, long-lasting engine. Your stock paper filter works great and really doesn't need a "mod" or an "upgrade."
10-02-2007, 10:15 AM
#11
MBWorld Fanatic!
I don't disagree with most of this. However, 100g is almost 1/4 of a pound of dirt. I believe I'm familiar with this test, and it was designed to make the K&N look bad. We don't drive dirt roads and I don't work for, or promote K&N or any other filter. For off road use, K&N adds a pre-filter to their installations. It may be called "coarse dust", but even the stock filter passed quite a bit of it. We can find plenty of other tests that make the K&N, Green, BMC, et. all. look like a good idea. The fact is, the filter is cleanable, so how fast it loads is nearly a moot point VS a throw away paper filter. Like anything else in the performance world, you give something to get something. ANYTHING that increases power can and does shorten the life of the drivetrain, there's no avoiding it. Increase boost, you get more heat and a shorter life span. Flow more air, you might gain power, but you lose max filtration. For those who want the absolute maximum power, every little thing is going to add up. Personally, the very few HP that might be gained from any of these filters just isn't noticeable or worth the cost. I'm not sure anyone has been able to show a repeatable gain from a filter change?
Hey fast55:
I agree with EVERYTHING here
Espically the clean/throw out
My 89 stang had 275000 miles with a k/n, which is to say$35 bucks vs 22 x $14 for stock and had NO PROBLEMS.
My brothers 95 Camero had 225,000 with no problems.
I have used K/N's on EVERY car I have ever owned, with ZERO problems.
I don't have stock, nor am I employeed by them, but I have seen good results in evry car I drive.
My supercharged stang picked up 22HP over a paper filter on the dyno and that was when she was only 376 rwhp, and my G-tech showed my C32 was on average .11 seconds faster 0-60. 4.83 vs 4.94
I agree the gains are small, and NEW paper filters are probably almost as good, but for the buck, I will still use K/N's
Heck I even have one in my Taurus and the wifes Freestyle
Oh well, some say potatoe, some say potato.
See yeah
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