K&N Air filter Installation and Performance Analysis

[RuckinEMT]

I didn't see any difference in my Corvette when I added it. GM specifically states that a KN filter voids warranty and that it can cause damage and poor performance. It was well known that the oil residue used in those filters can be drawn in and plate the mass air flow sensor wire on a car and give erroneous resistance measurements to the CPU hence resulting in poor performance and those style air filters can attract dirt and plug sooner hence more cleaning. I dunno how it will function on a bike and even if they have a MAF.. but Maddiedog did a very good real world test .

I've used them on all my bikes, including my touring Harley's with no issue...

[chicaboo]

The only problem with K&N filters are the hot-wire air flow meters, otherwise they give good warm fuzzies.
The AFM on the PCX has a cylinder on a spring and measures airflow by resistance on the cylinder position.
When I inspected my AFM, there was no oil on it from the K&N filter. So I doubt it would cause any problems.

[clemence]

The OEM PCX paper filter is a viscous oily type. The crankcase vent hose connected to the OEM airbox intake also induce oil mist too. You can open and check the airbox, there's oil there. So, in small amount the oil will get burnt and cause little to no effect to the sensor readings.
But I'll never bother to use expensive K&N or any other similar design. Too noisy and not so weather proof, with minimal power gain (with proper injector remapping) for stock engine.

[u33db]

GM specifically states that a KN filter voids warranty and that it can cause damage and poor performance. It was well known that the oil residue used in those filters can be drawn in and plate the mass air flow sensor wire on a car and give erroneous resistance measurements to the CPU hence resulting in poor performance and those style air filters can attract dirt and plug sooner hence more cleaning.

I echo this.

On the car specific forum (GM in the UK) i am a member most people people avoid K&N and other oiled filters due to the MAF contamination issue.

My point-of-view isn't down to that, its simply down to the false economy; they are advertised as lifetime filter yet i have seen K&N's fall apart in under year. Even if they don't when you factor in the increased cost of the K&N plus the cleaning kit you could buy MANY years worth of standard filters and also not have the hassle of cleaning.

Longevity wise they don't filter as well as standard either - i value my engine!

Performance wise they'll maybe add 2-3 HP on a 200+bhp car so i don't see the point...so on a scooter...

[Eiron]

GM specifically states that a KN filter voids warranty and that it can cause damage and poor performance. It was well known that the oil residue used in those filters can be drawn in and plate the mass air flow sensor wire on a car and give erroneous resistance measurements to the CPU hence resulting in poor performance and those style air filters can attract dirt and plug sooner hence more cleaning.

I echo this.
On the car specific forum (GM in the UK) i am a member most people people avoid K&N and other oiled filters due to the MAF contamination issue.
My point-of-view isn't down to that, its simply down to the false economy; they are advertised as lifetime filter yet i have seen K&N's fall apart in under year. Even if they don't when you factor in the increased cost of the K&N plus the cleaning kit you could buy MANY years worth of standard filters and also not have the hassle of cleaning.
Longevity wise they don't filter as well as standard either - i value my engine!
Performance wise they'll maybe add 2-3 HP on a 200+bhp car so i don't see the point...so on a scooter...

I'd have to respectfully disagree with both easyrider and u33db. I've used K&N air filters on three Saabs (GM owned; two of them turbocharged) and one Chevy, and never had any of the problems described above. In one case I've used the same K&N continuously for 19 years, and multiple years of Used Oil Analysis on that engine have always shown extremely low (or none) dirt contamination. I believe the keys are to neither over-clean the filter nor over-oil it after cleaning. All of my filters get cleaned every 50,000 miles, and the 19 yr old filter has almost 200,000 miles on it. I've never bought them for any performance increase, but only for a very real economic and environmental savings. Based on the number of miles I put on my PCX here in Colorado, if I bought one I'd very likely never even have to clean it for the first 20 yrs I used it!

[Cube]

I have (or had) K&N filters in all my 4 wheel toys over the last 25 years and have never had any issues caused by the filter. The butt dyno always shows some power improvement regardless of engine displacement, even when installing used K&N filters off ebay. I make sure not to over clean or over oil them, in fact I'm still on my first can of filter oil from 25 years ago. I like that I can quickly clean and replace the filter whenever I think it needs it and not have to order one or run to the store. For all these reasons, I plan to keep using K&N and I plan to get them for both my PCX and my Silver Wing once the existing OEM ones get dirty.

The GM warranty issue is all anecdotal from what I can see, and in many references they are talking about the full CAI system, not a drop-in filter.

Bottom Line: If you think they are inferior, loud, dangerous, too expensive or your father's brother's cousin's former roommate once killed a MAF on his GM after using an entire can of oil - don't use them.

[neb4152]

I had big improvements in uphill torque, just where I wanted it. But with a new exhaust I am running lean. In the shop getting tuned.

[vamootsman]

I had big improvements in uphill torque, just where I wanted it. But with a new exhaust I am running lean. In the shop getting tuned.

How do you know you are running lean? And what Tuning can you do with just a AM filter and exhaust?

[Testerpt5]

Well just got my k&N filter and the cost here in Portugal was 66€, twice the US price.

[easyrider]

Simple...more air,more dirt.

[Marko]

K&N filters are expensive BS. They neither flow significantly more air or filter better than a stock Honda filter (or any other manufacturer). A complete waste of money.

[you you]

K&N filters are expensive BS. They neither flow significantly more air or filter better than a stock Honda filter (or any other manufacturer). A complete waste of money.

Other opinions are available.

[easyrider]

K&N filters are expensive BS. They neither flow significantly more air or filter better than a stock Honda filter (or any other manufacturer). A complete waste of money.

Other opinions are available.

Her's one more.especially on the end of the video

https://www.youtube.com/watch?v=NJKlb61_kXU

[BRTID]

Interesting. I think I might try it myself. Thanks for the info