replacing Stock air filter with K&N

[dwayne]

I've done this on my carbed bikes, and it involves rejetting...which I can do myself, but with a Fuel Injected bike; will the ECU compensate for the increased air flow, or do I need to look at having a new program installed by the dealer? I havn't asked the dealer about this yet: thought I would try here first.

[Oilhead]

Yeah no problem. The BMW is a closed loop so the ECU will compensate. I have had my K&N for about 3 years now and I just love the honking intake noise that it makes!

[dwayne]

Yeah no problem. The BMW is a closed loop so the ECU will compensate. I have had my K&N for about 3 years now and I just love the honking intake noise that it makes!

Thanks! I know I read about the bike having a closed loop system; but what does that actually mean?

[Oilhead]

Thanks! I know I read about the bike having a closed loop system; but what does that actually mean?

In a closed loop, the ECU compares the measured air/fuel raio and compares it to the targeted ratio and will automatically increase or decrease the fuel delivery. In an open loop, the ECU cannot increase or decrease the fuel delivery.

Our BMW has the closed loop so it will automatically increase the fuel for the increased air intake.

[dwayne]

...Our BMW has the closed loop so it will automatically increase the fuel for the increased air intake.

Excellent! Now one more little question: will this void the warrenty, or allow BMW to ever invoke the dreaded SB #2851 on me?

[Oilhead]

Excellent! Now one more little question: will this void the warrenty, or allow BMW to ever invoke the dreaded SB #2851 on me?

Young Jedi, you ask a lot of questions...haha jk.

Actually it's against the law to void a warranty for using another manufacturer's filter that meets the minimum specification. The only way they can do that is if they supply their own filters for no charge to the consumer.

[klrstix]

Yeah no problem. The BMW is a closed loop so the ECU will compensate. I have had my K&N for about 3 years now and I just love the honking intake noise that it makes!

Do you know what impact this has on gas mileage? Just wondering...

[dwayne]

...Actually it's against the law to void a warranty for using another manufacturer's filter that meets the minimum specification. The only way they can do that is if they supply their own filters for no charge to the consumer.

I am actually aware of that, but I am also aware that fighting that could end up costing me a lot of time and money. I'm sure BMW would not force the issue, but how much BS will you have to go through to get that far? Best to play by their rules...he who has the gold....

[Oilhead]

...Actually it's against the law to void a warranty for using another manufacturer's filter that meets the minimum specification. The only way they can do that is if they supply their own filters for no charge to the consumer.

I am actually aware of that, but I am also aware that fighting that could end up costing me a lot of time and money. I'm sure BMW would not force the issue, but how much BS will you have to go through to get that far? Best to play by their rules...he who has the gold....

Dwayne BMW is no Honda when it comes to customer service but I cannot even imagine even for one second that they would even remotely give you a hard time regarding warranty issues for using a K&N filter.

[Oilhead]

Do you know what impact this has on gas mileage? Just wondering...

Not much really. It only affects it at wide open throttle as it draws in a little more air. I always get about 40-45 mpg, before and after K&N.

[BigJugs]

Dwayne BMW is no Honda when it comes to customer service but I cannot even imagine even for one second that they would even remotely give you a hard time regarding warranty issues for using a K&N filter.

My local dealer doesn't agree with your statement. They are a Honda dealer first, BMW second and they told me that Honda is very fickle on warranty claims whereas BMW typically pays warranty claims without hassle.

[CycleRob]

K&N filters dirt trapping ability is just as good as the stock paper filter (over time) only if it is properly serviced. I've performed many services (over 10 years) on Japanese SportBikes with K&N filtes already in place. In a majority of them, Yes . . . a majority of them, the velocity stacks on the clean side of the filter have a fine silt muddy film that is clearly visible. One finger swipe and your finger is dirty. Those K&N filters held up to a bright light just glitter with brightness. Those points of light glitter also let thru "dirt fines" that will hone your cylinderwalls and pistons to an equivalent mileage of many times your bikes odometer reading.

Reading the strongly worded, plain English instructions on the necessary K&N filter cleaning kit apparently isn't on many K&N filter owner's list. They must be ignoring them, even after being warned about it at purchase time . Things like solvents, blowguns, rough physical treatment or hair dryers are forbidden. Obviously, so is "setting it and forgetting it".

The large amplitude pulsing of the OilHead's intake airflow is quite hostile to filter media. The stock paper filter is under $12 from our friendly Chicago BMW dealer* and appears to still look like new and last beyond their recommended conservative replacement interval. Granted, my actively avoiding rain riding and following dirty trucks factors in to that longevity - - - but so does the self cleaning nature of the filter itself. I'm talking about that hostile intake pulsing -and- the position of the filter that, when particles of all sizes are dislodged, they fall down & away from the filter paper to later disappear out the tiny sand/water hole in the floor bottom of the airbox's dirty side.

My shop sells K&N filters and as half owner, I can acquire the K&N filter cleaning kit and OilHead K&N filter at dealer cost. My bike always has a stock paper BMW filter in it.

* They offer 20% off all genuine BMW parts. Approx $9 S&H charge applies, so place a significant order of necessary parts to make your order less than your local dealer's cost. I am not affiliated with them in any way . . . I just think you could save a LOT on a big or yearly order.

[dwayne]

...the velocity stacks on the clean side of the filter have a fine silt muddy film that is clearly visible. One finger swipe and your finger is dirty. Those K&N filters held up to a bright light just glitter with brightness. Those points of light glitter also let thru "dirt fines" that will hone your cylinderwalls and pistons to an equivalent mileage of many times your bikes odometer reading...

That's the kind of statement I was hoping for. Not so much a negative against K&N, but rather a non-biased opinion. Thanks Rob.

The K&N is off the list. All I needed was one negative statement to sway me.

[Rog(UK) - Yorkshire Dales]

I'm afraid I haven't got hard facts here, but I seem to remember, two or three years ago, reading a thread on the Moto Guzzi Forum relating to this issue.

The K&N's scored well, but the stock paper filter removed the most particulates but needed renewing more frequently. ie it was more efficient.

Don't take it as gospel. I'm sure the relevant web-page is still there -somewhere!


Rog.

[Kazushi]

Just the other day I asked the local dealer about a "K&N Kit" they had on display, where they claimed a 8-9 HP increase !?

The kit included an air filter, spark plugs, and all involved hoses...
They claimed that 1) The bike sound will change, 2) The consumption will rise, 3) The performance will increase...

All of the above for "just" 300 Euro...

Yeah no problem. The BMW is a closed loop so the ECU will compensate. I have had my K&N for about 3 years now and I just love the honking intake noise that it makes!

Do you know what impact this has on gas mileage? Just wondering...

[Kazushi]

More than a year later I went through with it, paid 270 Euro and had the kit installed !

The R now sounds much sexier (the air intake sound is really cool!) and the throttle reacts much better and smoother now !

Haven't really checked gas consumption yet, but who cares as long as the R runs better :-)

Just the other day I asked the local dealer about a "K&N Kit" they had on display, where they claimed a 8-9 HP increase !?

The kit included an air filter, spark plugs, and all involved hoses...
They claimed that 1) The bike sound will change, 2) The consumption will rise, 3) The performance will increase...

All of the above for "just" 300 Euro...

Yeah no problem. The BMW is a closed loop so the ECU will compensate. I have had my K&N for about 3 years now and I just love the honking intake noise that it makes!

Do you know what impact this has on gas mileage? Just wondering...

[b52bombardier1]

Hello,

A few years ago, on one of the BMW M3 car sites, somebody did a fairly scientific oil analysis study between the oil in a K & N equipped bike and a regular stock paper filter equipped bike. The numbers for particulates and general purpose junk in the K & N oil was nowhere near as good as the bike with the paper filter. It was particularly high on things like silicon which is predominant in plain old sand.

Yea, I may give up a few horsepower with the paper filter but I like longevity in my engines better than I like higher power. Just a little food for thought . . .

Rick
95 BMW M3
2002 R1100S
2004 R1150RT

[Sunbeemer]

I have to agree with Cyclerob (again!) about his assessment born of experience with the K&N air filter. While I have not had them on a car or motorcycle, we have them on three high-performance diesels in a boat and they have been a source of concern by allowing exhaust contaminants to pass into the engines that prematurely scored the cylinder walls and wore the rings. Unfortunately, these engines inspire a lot of air and there is little room to mount equivalent sized paper filters, so we must use them and they are better than nothing. In the engine room, as on our bikes, the filters are subject to high temps which apparently dries the filter oil out of them fairly quickly, necessitating weekly to monthly re-oiling depending on the season to maintain their filtering ability. Still, when you peer through them in the sunlight, you can see many, not-too-smallish holes that let air and dirt pass through. We also find a disconcerting amount of residue in the air intake plenums.

While I think they are suitable for racing environments to squeeze out that extra horsepower or two on the (clean) track, I wouldn't consider using them on the (dirty) road for the long haul. I think if you do, your engine won't haul you as long.

[Airman]

I guess I can see paying the premium for the K&N if there if you really get better filtering, but performance ? I can't see how you can get any without increasing the intake volume. One of the guys here some time ago installed that airbox kit from San Jose BMW. It uses the K&N filter but also has a larger air intake tube, and involves cutting a 4" hole in the bottom of the airbox. I asked him what the perfomance gains were. Increased airflow at the intake side is only going to help if you also increase flow on the exhaust side, so he had installed the whole package including chip and aftermarket exhaust. I seem to recall it increased his top end from 125 to 136 without real power gains in the low end. For what, $14 ? I'll just replace the paper filter if I'm taking the trouble to take the tank off to inspect it anyhow.

[Kazushi]

There is an interesting test on the net:

http://home.stny.rr.com/jbplock/ISO5011/SPICER.htm

Not our kind of engine or type of filter, however it does give you a good idea !

If you remember the URL for the analysis you mentioned, I'd love to see it.

In any case, it is truth that there's always a downside to everything...

D.

Hello,

A few years ago, on one of the BMW M3 car sites, somebody did a fairly scientific oil analysis study between the oil in a K & N equipped bike and a regular stock paper filter equipped bike. The numbers for particulates and general purpose junk in the K & N oil was nowhere near as good as the bike with the paper filter. It was particularly high on things like silicon which is predominant in plain old sand.

Yea, I may give up a few horsepower with the paper filter but I like longevity in my engines better than I like higher power. Just a little food for thought . . .

Rick
95 BMW M3
2002 R1100S
2004 R1150RT