I simply prefer to keep as much dirt as possible out of my combustion chamber and related system components. I think that is the right approach since the OEM filter provides all of the air necessary to hit its 300+ horsepower rating. So why mess with it? Keep as much dirt out as possible. I don't know, seems like simple logic to me.

A drop in K&N will do nothing (next to nothing) for you relative to a performance gain. The OEM provides the necessary air flow across the full spectrum of engine RPM and gearing. Somebody mentioned that at passing speed you might see some additional performance, okay, perhaps so, but at 300+ horsepower, I just don't have issues passing folks. But extra power would be a benefit.

Look at my pictures of the pre and post cat O2 sensors and you can see the accumulation of "crud" on the pre-cat sensors. How much of that is K&N related? I have no idea, but logic would seem to indicate that it would have been lower if the guy had stayed with OEM.

I really have no idea how long the guy had the K&N in the car. When I held it up to the sun (as in the photos), it's easy to see right through it. Yet, it has the appearance (kind of black looking in some areas) of having some miles on it. I'm not sure how to read that. It's easy to see through which seems odd/weird to me. The sun can actually be visible right through it without any media to block it. It's certainly the most porous filter I've ever held up to the sun.

That brings me to the intake silencer and accumulation of "crud" on it. I can find very little information about this item relative to cleaning it? replacing it? how often? etc.,

I would suggest people look at the study and realize that a K&N is a trade-off just as the OEM is a trade-off. K&N is greater air flow. OEM is greater filtration. Neither one is offering both.

 

By the same token, you need to do your research. The benefits of greater airflow are verified, however, your claim of increased contaminants causing damage are not. My in-laws have a 2000 Honda Accord, it has 275k miles on it, it has had a K&N since 2000, not a single issue other than regular maintenance. I know of several other identical stories.
As I said, I have used K&N for over 10 years in a variety of cars, none of which had an single engine problem.

 

This has been entertaining to read, thanks all!

Apparently many of you lack basic/fundamental reading-comprehension skills, which is sad as I always thought the German premium-car-demographic was a bit more intelligent, than say the Civic or RSX tuning forums. I bring this up, as many of us on here laugh/make fun of these 16 year old kids who buy a beaten-to-hell Teg throw an eBay muffler on it as well as a dozen "performance" stickers, and then try to go Fast & the Furious on the locals. Then -- when they get called out, the get really defensive and angry.

But lets all be honest here -- this is the exact same thing that is going on in this thread. A group of us are saying "Sure the K&N doesn't do much-if anything to an otherwise n/a car other than let more crap into the engine." Thereafter a few of you start name-calling, and getting all bent out of shape because your automotive ethos is being challenged by facts you cannot refute. Then you beging to substantiate your claims with anecdotal evidence -- its not a good look. E.g., "Herp-derp an Accord with a K&N went forever yo! You must blame others for your problems ..." etc., etc., etc.,

So, we can all admit that the K&N does let in more crap -- which is not good for the motor -- and its performance gains on an otherwise n/a car are zero to infinitesimally miniscule or you can keep arguing against common sense stuff like water being wet and more resemble this kid;



driving this;



Your choice.

 

Gatriel,

One word, Kudos!

 

[QUOTE=Gatriel;1491100]This has been entertaining to read, thanks all!


So, we can all admit that the K&N does let in more crap -- which is not good for the motor -- and its performance gains on an otherwise n/a car are zero to infinitesimally miniscule or you can keep arguing against common sense stuff like water being wet and more resemble this kid;


Well said! The only theoretical gain by reducing the pressure drop in the air supply system (manifold) by eliminating restriction through filters doing their job, is 'pumping loss'. Putting in a less efficient (filtering wise) filter (K&N or other) to reduce pressure drop for the SAME airflow, does not reduce the 'pumping loss' even close to significantly. Believe me, I am an engineer and I have done the math1

Salut, Bob p.

 

Funny Gatriel, I resorted to zero personal attacks, I just presented examples of longevity using K&N filters. You (and others) are the one that seems to have no evidence of even a single case where engine damage can be attributed to the use of a K&N filter. All I have seen is a study, probably sponsored by a paper element filter maker, showing alleged additional contaminants entering the engine. I even said that there is little or no difference without other mods to augment it, such as an RPI scoop, exhaust, and tune.
As is typical of those with small brains and probably even smaller genitalia, you have to name call and pout around like a spoiled child when you are presented with a evidence contrary to your point of view.

Let's look at BMW's engineers have erred in the recent past, shall we?
High Pressure Fuel Pumps in 535's
Useless Charcoal filter in US cars in the intake that only serves to restrict airflow
Faulty passenger air bag seat sensors
Faulty window regulators
Squealing brakes
Brake booster pump (V8 Engines)
Intake coolant pipe (V8 engines)
Plastic coolant expansion tanks that crack
Transmissions that slam when they shift
Need I go on? Want to explain to me how superior the BMW engineers are to the aftermarket?
I am not talking about a difference of opinion, everyone is entitled to do as they please, I am talking about evidence.

 

Pjinca, most, if not all of the so-called engineers' errors were actually the accountants' fault! They didn't authorize the engineers' choices.

We aren't saying that there is evidence of engine harm due to K&N filters, but that there is NO benefit in using them, but the theoretical possibility of damage, especially if one is not changing one's oil frequently.

And please, let's not get into the 'mine is bigger than yours, therefore I am right' nonsense.

Respectfully, Bob P.

 

I presented a scientific study performed in a controlled environment that proves that K&N allows in more dirt than any other OEM (and most after-market) filters. That's a fact. Why do I want to do that? And for this my mental capabilties are called into question?

I have a Valvetronic (N62) engine wherein the valves control the amount air allowed into the combustion chamber and the traditional throttle function is gone. Stomping on the gas pedal simply sends my "wish" electronically to the Valvetronic system to monitor the amount of fuel and air that the 8 chambers receive.

This variable lift of the valves takes the amount of air control away from the throttle plate and places its 100% in the hands of the valve lift control microprocessor. The valves lift is ALWAYS controlling (varying) the air flow, and they are NEVER starved for air with an OEM filter.

So you can leave your filter out if you want, but the Valvetronic system will still control how much air is allowed into the combustion chamber at any instant. From minimal (idle) to full valve lift, the OEM filter is always presenting enough air to accomplish the task at peak efficiency. And from min to max, valve lift occurs in under 3/10ths of a second.

So it's not the throttle plate controlling air flow but each individual valve lift on each cylinder opening and closing a varied amount that allows air in. The engine is never starved for air.

So all you're going to do, is allow more dirt into the chamber which could interfere with combustion, collect on spark plugs, O2 sensors, etc but the valves microprocessor will still control the AMOUNT of air.

 

Boooorring. Tired of this now. Time for all participants to move on to a "Sprintbooster - miracle, placebo or the Devil?" thread.

 

Boring?

I think the N62 engine is a masterpeice of engineering excellence! Especially the variable valve lift and timing functionality.

If you're bored talking about BMW engines, then what mass produced engine turns you on?