K&N Air Filter

cworley5150 · Post by **cworley5150** » Tue Jan 16, 2007 9:42 am

Anybody here replaced your filter with a K&N? I will be doing my 12k mile service soon. Looking for a replacement filter. I ahve used K&N filters on other cars and bikes before with good results. Just wondering if there are any issues with putting one in the Rockster. I have stock exhaust, but I am currently running without the can on the bike. Any problems with running too lean?

Thanks!

priapismic · Post by **priapismic** » Tue Jan 16, 2007 1:47 pm

I've been running one on my '04 for a few years now. I'm currently at 38k miles and have no known issues.

One piece of advice - take that puppy out when you do an annual service and clean it. K&N filter charger kits are available at auto parts stores, and you'll find it worth your while to clean the crud off once in a while. I know, I know, they're supposed to work better as they gather dirt, but one look at the crud caked on to mine and I knew it had to be cleaned - no way was it gonna filter anything through that mess.

Post by **ProductUser** » Tue Jan 16, 2007 2:05 pm

I ahve used K&N filters on other cars and bikes before with good results

What kind of results?

ProductUser

cworley5150 · Post by **cworley5150** » Tue Jan 16, 2007 3:30 pm

ProductUser wrote:
I ahve used K&N filters on other cars and bikes before with good results
What kind of results?

ProductUser

I replaced the entire air box on a 1988 Ford T-bird Turbo Coupe with a K&N cone type filter. This made a huge difference in the performance on that car. It allowed the turbo to spool up quicker. It didn't totally eliminate the turbo lag that the car had, but it helped quite a bit.

I also had a K&N replacement filter in an 1100 Honda that helped improve the performance along with other mods I had done.

I'm not so much interested in HP gains or gas mileage gains on the Rockster. Although if there are any, I would be happy. I just like the idea of a cleanable and reusable filter.

cworley5150 · Post by **cworley5150** » Tue Jan 16, 2007 3:32 pm

priapismic wrote:I've been running one on my '04 for a few years now. I'm currently at 38k miles and have no known issues.

One piece of advice - take that puppy out when you do an annual service and clean it. K&N filter charger kits are available at auto parts stores, and you'll find it worth your while to clean the crud off once in a while. I know, I know, they're supposed to work better as they gather dirt, but one look at the crud caked on to mine and I knew it had to be cleaned - no way was it gonna filter anything through that mess.

Thanks for the response. Yes, they do need cleaning/reoiling now and then. An annual cleaning is probably good.

johno · Post by **johno** » Wed Jan 17, 2007 2:01 am

According to my BMW guru, K&N filter waste of time and money.
Genuine does the job good according to him.
The biggest limit is the air box design, not the filter.

Oilhead · Post by **Oilhead** » Wed Jan 17, 2007 9:07 am

The K & N costs a little more than the OEM filter but if you are going to keep the bike for a while, it will save you money as it will last the usesable life of the bike.

The nice thing about our bike is that it will automatically compensate for any change in the airflow.

The actual results?

I can't really say I notice any seat of the pants difference but on my 2002 R1150R I was very pleasantly surprised to hear the deep low honk of the intake. It is noticeable louder than stock yet a very pleasing(to my ears) sound.

That alone was worth the price of admission.

Post by **CycleRob** » Wed Jan 17, 2007 6:00 pm

According to my BMW guru, K&N filter waste of time and money.
Genuine does the job good according to him.
The biggest limit is the air box design, not the filter.

I agree. The higher filter cost PLUS the mandatory cleaning kit's cost eats away at the savings. My biggest protest is based on all to commonly observed velocity stack dirt deposits passed by K&N filters not serviced EXACTLY as clearly stated on the K&N cleaning kit's box. NO compressed air, NO solvents, NO hair dryers, NO motor oil, etc . . . . everything that most people don't even hesitate to do as SOP.

The paper filter's retention specs are the best. Hold any new, newly oiled K&N filter up to a very bright light (NOT the Sun!!!). See those thousand points of light? Those are the fine silt passageways. Do the same with a new BMW paper filter. Dark, isn't it? The K&N's higger performance higher airflow is available at the sacrifice of miniscule top end wear.

If K&N type filters were better, like heated grips, shaft drive, 4-way flashers, 700Watt alternators, EFI, JumpStart lugs, Power Sockets and CenterStands are, BMW would'a put it on at the factory, the R1200R not withstanding.

GeoffJ · Post by **GeoffJ** » Thu Jan 18, 2007 1:25 pm

CycleRob wrote:
If K&N type filters were better, like heated grips, shaft drive, 4-way flashers, 700Watt alternators, EFI, JumpStart lugs, Power Sockets and CenterStands are, BMW would'a put it on at the factory, the R1200R not withstanding.

Oh, like the old EFI system that surged, huh? (just kidding)

NachtRitter · Post by **NachtRitter** » Fri Jan 19, 2007 1:06 am

CycleRob wrote:If K&N type filters were better, like heated grips, shaft drive, 4-way flashers, 700Watt alternators, EFI, JumpStart lugs, Power Sockets and CenterStands are, BMW would'a put it on at the factory, the R1200R not withstanding.

I have to disagree with the statement "if x were better, BMW would'a put it on at the factory." I think there are a lot of "better" things that could be on the BMW 'bikes (in general, not just the R1150R) (such as seats, mirrors, wind screens, lights, tires, etc) but aren't put on at the factory for various reasons (cost, manufacturability, long term maintenance, co-branding, etc). I don't see anything wrong with that; it allows us to afford the 'bikes and add what we believe to be "better". If Oilhead and priapismic think the K&N is better, I'm interested in hearing the reasons. If someone else thinks more lights or additional gauges are better than what the factory provides, then I'm interested in hearing the reasons. The fact that BMW didn't put that stuff on at the factory is not a good 'nuff argument to say it's not better.

[/rant]

Post by **CycleRob** » Fri Jan 19, 2007 2:06 am

NachtRitter,
Point taken. My "If it were better" logic was a hasty and popular reply. Engineers and bean counters prolly do not use that logic. I still stand with the OEM paper filter as offering the cleanest air to the engine and the thousand points of light test gives anyone the visual proof.

Both the K&N type filter's high initial cost and strict service procedure required would rule them out as OEM parts, which favors remove-n-replace. So much easier to just plop in another paper filter every other valve adjustment.

Buying a K&N for more power is another small matter. The OilHead motor, like most new bikes, doesn't give you much when you throw performance dollars at it. With our bike it's only small gains unless you change the camshafts. For me, it's 80.3 dyno'd HP is enough power. Sacrificing $$$, the fat low+mid range torque and trip 53 MPG capability are not worth the camshaft changes, even though the labor is free.

NachtRitter · Post by **NachtRitter** » Fri Jan 19, 2007 3:15 pm

CycleRob wrote: Point taken. My "If it were better" logic was a hasty and popular reply. Engineers and bean counters prolly do not use that logic. I still stand with the OEM paper filter as offering the cleanest air to the engine and the thousand points of light test gives anyone the visual proof.

Yep, I'm with you on everything else you said. I too am quite happy with the power the R-R provides; just by virtue of it being much lighter than my R-RT, it seems a heck of a lot faster. I'm thinking that'd be the best way to improve performance... lose wieght!!