[wagonmaster]

Anyone run K & N air filters? I've always run them, but I've had mostly trucks. Any recommendations not to? Thanks!

[bartman32]

I did on my e46 and it always seemed to run well. I'm sure I will on my e92 when I get it and when K&N makes one for it.

[KL2DC]

I have the drop-in filter. I can't say with certainty if there has been a noticeable benefit. I think at best I can appreciate more intake sound.

[wuufer001]

does the air filter help also with the intake sound, cause i thought only the cold air intake will help.

[Kung Pao]

I've run K&N on multiple cars, both drop-in filters and a full short-ram intake. They all do the same thing for the most part, which is make the engine run a hair smoother and the intake sucking sound becomes a little more noticable. Sound from the engine isn't changed a whole lot, maybe a little bit more growl. It's a nice addition though

[simp0man]

Yesterday I had my 328i placed with a K&N filter drop-in and the engine seems to rev more faster, I think better air is coming in. Plus I took off the carbon filter so that totally allowed better flow. The stock air box is good enough. It practically is cold air intake since the air dam is coming directly from outside. I wish there was a way to encorporate the vent for the brake to go into the air box instead but then that would cause the brakes to work unevenly. It may create more deposits in the engine but if I change my oil frequently then the intended 15k miles, I think I am good.

[aapriadi]

i have a question: advanced auto parts sells this filter and i wonder if i should let them install it as well? they will do it for free if i buy it from them, the store is close to home and i've talked to some of the guys there

[KL2DC]

aapriadi...dude, its an easy 30 min (at most) DIY

I'd do it myself, so I can baby that sensitive air sensor.

[Kung Pao]

Originally Posted by aapriadi

i have a question: advanced auto parts sells this filter and i wonder if i should let them install it as well? they will do it for free if i buy it from them, the store is close to home and i've talked to some of the guys there

I'd do it myself, it takes like 20 minutes

EDIT: I see this was already posted

[simp0man]

It is very simple. Just be very careful with the air sensor, just a little lift to get that snap up and pull it off.

[NaTuReB0Y]

I have the drop-in K&N filter......the only difference is +2 mpg.

Instead of getting 23 mpg....I'm getting something in the neighborhood of 25+ mpg

[Chesmu]

Originally Posted by simp0man

I wish there was a way to encorporate the vent for the brake to go into the air box instead but then that would cause the brakes to work unevenly. It may create more deposits in the engine but if I change my oil frequently then the intended 15k miles, I think I am good.

Ksfrogman did this to his: "salt shaker mod"
and this is what the DINAN system is.

[simp0man]

Awsome tip, Chesmu!!!

[simp0man]

Originally Posted by NaTuReB0Y

I have the drop-in K&N filter......the only difference is +2 mpg.

Instead of getting 23 mpg....I'm getting something in the neighborhood of 25+ mpg

Shoot, I've been averaging 23mpg that is with city and highway. So am I loosing some horsepower after this mod?:mad:

[Johnny Lin]

I hve it on my current 06 E90. Any how, I do not really feel anything. I guess it just b/c it does not increase that much MPH. So.. Good LUCK!

[Max_!]

You don't want a K&N.

You think you do but you don't. I'll tell you why:

1) A K&N filter will let more dust and dirt pass than a paper filter. (Says so right on their website). More dirt means more wear. How much more wear depends on how much dust you drive through. Of course, ancient design truck engines are less likely to suffer quickly than close-tolerance modern engines. You can send an oil sample to a local lab before and after a filter change and ask for the percentage of wear metals in the oil. With a K&N filter, there will be more sand and more metal in your oil. The sand and that metal has to come from somewhere.

2) A K&N will happily pass grit particles larger than the width of the oil film in your engine bearings - again, they don't hide this, it's right on their website. Together with #1, this spells disaster. The dust particles first sand down the intake valves, then some of those stick to the cylinder wall and get scraped into the sump. Some of these get into your oil filter. If enough of these clog the oil filter, the bypass opens, pumping grit at high pressure into your bearings. In relative sizes, it's boulders gauging out canyons in your bearings.

3) If you have a turbo, these dust particles impact the blades at high velocity, sanding them down, causing imbalance. They also get into the bearings. Both cause performance loss and turbo failure. This is why cars with performance filters have so many turbo failures, it's not always because of the higher boost as many think.

4) All K&N filters will loose some oil, and oil covered particles, into the intake. If you have MAF, these particles coat the wire or tile and reduce it's ability to accurately gauge the mass of air, causing performance problems such as rough running and increased milage. These particles also stick to intake valves, wedging them open and sanding down the valve seats, causing performance loss.

5) A K&N filter does not improve performance. Yes, if you cut off half the intake and replace it with a cone filter you will probably see a performance increase but this has nothing to do with magical filter material - You removed half the intake! A BMW has a properly dimensioned intake duct and filter. If you measure the power output on a rolling road and you replace the stock paper filter with a K&N or even remove the filter alltogether and leave the filter box empty, you will get exactly the same result each time.

Federal Mogul - manufacturer of engine components - found that over half of all engine failures it investigated where caused by ingested dirt.

Of course, the engine won't crap out in the first 500 miles, so by the time the wear becomes obvious, 40K or so, you've probably sold the car or you attribute the drivability problems to other causes.

Now you can make an informed choice.

My advice to anyone: use a stock paper filter and a stock oil filter and replace them often.

Max

[NaTuReB0Y]

Originally Posted by Max_!

You don't want a K&N.

You think you do but you don't. I'll tell you why:

1) A K&N filter will let more dust and dirt pass than a paper filter. (Says so right on their website). More dirt means more wear. How much more wear depends on how much dust you drive through. Of course, ancient design truck engines are less likely to suffer quickly than close-tolerance modern engines. You can send an oil sample to a local lab before and after a filter change and ask for the percentage of wear metals in the oil. With a K&N filter, there will be more sand and more metal in your oil. The sand and that metal has to come from somewhere.

2) A K&N will happily pass grit particles larger than the width of the oil film in your engine bearings - again, they don't hide this, it's right on their website. Together with #1, this spells disaster. The dust particles first sand down the intake valves, then some of those stick to the cylinder wall and get scraped into the sump. Some of these get into your oil filter. If enough of these clog the oil filter, the bypass opens, pumping grit at high pressure into your bearings. In relative sizes, it's boulders gauging out canyons in your bearings.

3) If you have a turbo, these dust particles impact the blades at high velocity, sanding them down, causing imbalance. They also get into the bearings. Both cause performance loss and turbo failure. This is why cars with performance filters have so many turbo failures, it's not always because of the higher boost as many think.

4) All K&N filters will loose some oil, and oil covered particles, into the intake. If you have MAF, these particles coat the wire or tile and reduce it's ability to accurately gauge the mass of air, causing performance problems such as rough running and increased milage. These particles also stick to intake valves, wedging them open and sanding down the valve seats, causing performance loss.

5) A K&N filter does not improve performance. Yes, if you cut off half the intake and replace it with a cone filter you will probably see a performance increase but this has nothing to do with magical filter material - You removed half the intake! A BMW has a properly dimensioned intake duct and filter. If you measure the power output on a rolling road and you replace the stock paper filter with a K&N or even remove the filter alltogether and leave the filter box empty, you will get exactly the same result each time.

Federal Mogul - manufacturer of engine components - found that over half of all engine failures it investigated where caused by ingested dirt.

Of course, the engine won't crap out in the first 500 miles, so by the time the wear becomes obvious, 40K or so, you've probably sold the car or you attribute the drivability problems to other causes.

Now you can make an informed choice.

My advice to anyone: use a stock paper filter and a stock oil filter and replace them often.

Max

With this info........if anyone is getting rid of their GruppeM with K&N filter.....

I'll take it off your hand for $125.......my maximum offer.

[E90330iS]

Originally Posted by NaTuReB0Y

With this info........if anyone is getting rid of their GruppeM with K&N filter.....

I'll take it off your hand for $125.......my maximum offer.

Hahaha! I remember I bought a K&N filter also but I read that it lets more dirt go in the engine so I sold it to my friend without even reinstalling it

[Biemdreamer]

Originally Posted by Max_!

You don't want a K&N.

You think you do but you don't. I'll tell you why:

1) A K&N filter will let more dust and dirt pass than a paper filter. (Says so right on their website). More dirt means more wear. How much more wear depends on how much dust you drive through. Of course, ancient design truck engines are less likely to suffer quickly than close-tolerance modern engines. You can send an oil sample to a local lab before and after a filter change and ask for the percentage of wear metals in the oil. With a K&N filter, there will be more sand and more metal in your oil. The sand and that metal has to come from somewhere.

2) A K&N will happily pass grit particles larger than the width of the oil film in your engine bearings - again, they don't hide this, it's right on their website. Together with #1, this spells disaster. The dust particles first sand down the intake valves, then some of those stick to the cylinder wall and get scraped into the sump. Some of these get into your oil filter. If enough of these clog the oil filter, the bypass opens, pumping grit at high pressure into your bearings. In relative sizes, it's boulders gauging out canyons in your bearings.

3) If you have a turbo, these dust particles impact the blades at high velocity, sanding them down, causing imbalance. They also get into the bearings. Both cause performance loss and turbo failure. This is why cars with performance filters have so many turbo failures, it's not always because of the higher boost as many think.

4) All K&N filters will loose some oil, and oil covered particles, into the intake. If you have MAF, these particles coat the wire or tile and reduce it's ability to accurately gauge the mass of air, causing performance problems such as rough running and increased milage. These particles also stick to intake valves, wedging them open and sanding down the valve seats, causing performance loss.

5) A K&N filter does not improve performance. Yes, if you cut off half the intake and replace it with a cone filter you will probably see a performance increase but this has nothing to do with magical filter material - You removed half the intake! A BMW has a properly dimensioned intake duct and filter. If you measure the power output on a rolling road and you replace the stock paper filter with a K&N or even remove the filter alltogether and leave the filter box empty, you will get exactly the same result each time.

Federal Mogul - manufacturer of engine components - found that over half of all engine failures it investigated where caused by ingested dirt.

Of course, the engine won't crap out in the first 500 miles, so by the time the wear becomes obvious, 40K or so, you've probably sold the car or you attribute the drivability problems to other causes.

Now you can make an informed choice.

My advice to anyone: use a stock paper filter and a stock oil filter and replace them often.

Max

Appreciate the food for thought. However, given all of the disadvantages stated above, why would DINAN include an K&N with their ram intake? I am under the impression that anything DINAN does is endorsed/accepted by BMW and won't void warranty.....seems that allowing an air filter to be used which really would damage a close tolerance engine would be a no no for warranty issues.....Just me thinking with my fingers on the keyboard....any thoughts?

[NaTuReB0Y]

AEM also uses K&N filter...........

[Max_!]

Someone I went to school with set himself up as a serious engine tuner. He took out a huge loan, bought a load of equipment and opened up a shop and started taking demo cars to shows and track events...but nomatter what he said or did or how good the power graphs looked, or how well his cars did on the track, nobody would take him seriously because he didn't use performance filters.

I'm not kidding.

For the longest time he simply refused to use anything except quality paper filters. But then money started to run out and he caved. He's now selling K&N's faster than the can drag them to his shop. I'm sure the truckloads of cash he's making selling those oiled bedsheets go a long way to ease his conscience because he doesn't exactly look miserable...

So if you ask why a tuner uses K&N filters... My guess would be it's because his customers expect it?

Anyway, he still doesn't run his pet projects with anything but a paper filter, he just swaps them out for a K&N for shows.

[The Cleaner]

Originally Posted by Max_!

You don't want a K&N.

You think you do but you don't. I'll tell you why:

1) A K&N filter will let more dust and dirt pass than a paper filter. (Says so right on their website). More dirt means more wear. How much more wear depends on how much dust you drive through. Of course, ancient design truck engines are less likely to suffer quickly than close-tolerance modern engines. You can send an oil sample to a local lab before and after a filter change and ask for the percentage of wear metals in the oil. With a K&N filter, there will be more sand and more metal in your oil. The sand and that metal has to come from somewhere.

2) A K&N will happily pass grit particles larger than the width of the oil film in your engine bearings - again, they don't hide this, it's right on their website. Together with #1, this spells disaster. The dust particles first sand down the intake valves, then some of those stick to the cylinder wall and get scraped into the sump. Some of these get into your oil filter. If enough of these clog the oil filter, the bypass opens, pumping grit at high pressure into your bearings. In relative sizes, it's boulders gauging out canyons in your bearings.

3) If you have a turbo, these dust particles impact the blades at high velocity, sanding them down, causing imbalance. They also get into the bearings. Both cause performance loss and turbo failure. This is why cars with performance filters have so many turbo failures, it's not always because of the higher boost as many think.

4) All K&N filters will loose some oil, and oil covered particles, into the intake. If you have MAF, these particles coat the wire or tile and reduce it's ability to accurately gauge the mass of air, causing performance problems such as rough running and increased milage. These particles also stick to intake valves, wedging them open and sanding down the valve seats, causing performance loss.

5) A K&N filter does not improve performance. Yes, if you cut off half the intake and replace it with a cone filter you will probably see a performance increase but this has nothing to do with magical filter material - You removed half the intake! A BMW has a properly dimensioned intake duct and filter. If you measure the power output on a rolling road and you replace the stock paper filter with a K&N or even remove the filter alltogether and leave the filter box empty, you will get exactly the same result each time.

Federal Mogul - manufacturer of engine components - found that over half of all engine failures it investigated where caused by ingested dirt.

Of course, the engine won't crap out in the first 500 miles, so by the time the wear becomes obvious, 40K or so, you've probably sold the car or you attribute the drivability problems to other causes.

Now you can make an informed choice.

My advice to anyone: use a stock paper filter and a stock oil filter and replace them often.

Max

+1 good to see the filter myth is being broken. Anyone that thinks they get performance out of a filter change should post the results. It just does not happen.