K&N Air Filter

[IndianaHarvey]

Just the other day I put in a K&N air filter on my 2005 R1200RT with 28K on it. Right off the bat I noticed the bike seemed to idle even smoother than before. On the ride to work the engine seemed to have more power in every gear. There's one freeway on ramp I would usually downshift from 6th to 5th, this time it went right up it in 6th. K&N says the filter is good for 1 million miles and only needs to be cleaned and re-oiled every 50K. Just wondering if anyone else has tried a K&N on their bike?

In case you're interested, the part number for all R1200's is BM-1204 and the price is 59.48

[10ovr]

[Satguy]

I just can't resist....

 

A great product if you want dirt in your engine...

 

Never will a K&N be used in any of my vehicles. Been there, done it

[eng943]

I have not put one into the RT, but I have used them on or simmilar types on my modified cars.

 

As for the declaration that they allow more dirt or particulate in the engine, that is somewhat subjective. The variable being how often they are cleaned/maintained, and if that is done properly.

 

Just for conversations sake. Ford uses these types of filters now on the Mustang in a factory cold air kit.

 

My personal opinion is that they may or may not produce more power, depending on the vehicle and where the air restriction is. As for their use and reducing engine longevity by allowing more dirt in the bike. I would tend to disagree provided the maintenance is done accordingly.

[Woodie]

Hooked a few, eh Harvey?

 

 

 

[Redbrick]

Harvey.....You'll find this is one of those......

 

type of topics........

Do a Search (up and to the right) on K&N for a recent thread...

[Joe Frickin' Friday]

Most of this is reprinted from a similar discussion that took place last year.

 

Here's what I came up with after a six-second search of the web on this string:

 

"K&N" "air filter" flow pressure review comparison

 

These guys did a low-budget (but informative) road test on a Miata. According to their measurements, the K&N improved intake manifold pressure under WOT conditions by 0.12 percent. Yup, about one-eighth of one percent.

 

These guys did a rigorous flow/filtration bench test of nine aftermarket filters. As you examine their graphs, it's important to point out that the zero of the Y-axis is not always located on the X-axis; so while one bar of the graph might look ten times as tall as another, they might actually be representing very similar values, so make sure you check out the numbers! Some conclusions to be drawn from their plots:

 

• Filter efficiency: K&N lets the most dirt get through.
   
  
• Accumulative capacity: Compared to all the other filters in the test except one, the K&N will accept relatively little dirt before presenting the maximum permissible increase in pressure drop (10 inches of water).
   
  
• Initial restriction: the pressure drop across a brand-new K&N under test conditions was 4.54 inches of water. The worst filter (the AC-Delco paper filter) came in at 6.23 inches of water. Atmospheric pressure is 408 inches of water, so the respective manifold pressures were 401.5 and 403.2, for a flow (and probable performance) improvement of 0.4 percent. Such a tiny improvement simply will not register on a butt dyno.

As to the engineering sense:

• a paper filter is made of...paper. It won't withstand much of a pressure drop before it collapses inward, so it stands to reason that there really can't be much of a pressure drop across it to begin with...which agrees nicely with the data that testers are providing.
   
  
• The K&N website is big on testimonials (a standard snake oil marketing ploy), but small on actual test data. They did link to a couple of "independent lab filter test results (flat filter and round filter), but you'll note that they're rather cryptic (a far cry from my earlier Duramax link), and there's no comparison whatsoever with their competitors. If their products are as superior to their competitors as they claim to be, they should be dying to show us some flow bench comparisons. Or some dyno comparisons. Or some 1/4 mile comparisons. Something, anything! All of that is conspicuously absent from their site, and objectively measured (i.e. no butt dyno) test results found elsewhere on the web consistently run counter to K&N's marketing claims.

So there's a fair collection of objective measurements that suggest K&N ain't so great, and a troubling lack of objective measurements affirming K&N's greatness. When a single butt-dyno evaluation turns in a result that's contrary to all that objective data, I'm very inclined to dismiss it. Subjective evaluations are notoriously imprecise and subject to a long list of conscious and unconscious biases.

 

Not insignificantly, time separation affects perception, too. Example:

 

Test 1: Pick up a 10-pound rock in one hand and a 9-pound rock in the other at the same time, and you can probably tell which one is heavier.

 

Test 2: Pick up a 10-pound rock in one hand, get a feel for it, and put it down. Come back a half an hour later and pick up a 9-pound rock. You'll have a much harder time telling which one is heavier.

 

Unfortunately an informal "butt dyno" test is very much like Test #2 - except it's even worse, because the difference we're trying to observe is far less than ten percent. So when the results conflict with what cold hard instruments are reporting in repeated tests, the most prudent course of action is to discount the butt dyno results.

[Albert]

Excellent Mitch! Now that you've put that one to bed please start working on synthetic oil, ATTGATT and bacon intake vs. nutritional value.

[FrankBrown]

A great product. I've got 161,000 miles on my '05 12RT with a K&N filter in it for the last 150,000 miles. No dirt, no problems. Same with my ST1100, 246,524 miles with no dirt and no problems.

[JohnBeaven]

Frank.

I am curious. Have you had any major problems after 161000miles.

I have not heard of a higher mileage R1200RT.

[jaytee]

Excellent Mitch! Now that you've put that one to bed please start working on synthetic oil, ATTGATT and bacon intake vs. nutritional value.

 

Lets add to the list loud pipes, octane and earphones on a bike!

[FrankBrown]

John -- Knock on wood, I've had no major problems. I've just come back from trips to Vegas, CA and northern GA runnin' strong.

[JGP]

Hey Frank,

 

Have you washed your RT???? It's Jim formerly of Florida, (black R1200R)now of Michigan.

 

As far as the K&N filter, I (should say Jay K.) replaced the OEM filter at 6k, now with 22K I checked it in preparation for the trip to Johnson City Tn. and found the filter to flithy!!! So much for the 50K miles interval.

 

Frank are you going to the BMW OA rally?

 

take care

 

jim

[Ken H.]

A great product. I've got 161,000 miles on my '05 12RT with a K&N filter in it for the last 150,000 miles. No dirt, no problems. Same with my ST1100, 246,524 miles with no dirt and no problems.

Personally, if I DIDN’T have dirt in my filters I’d be worried. That’s what they’re there for. If it isn’t in the filter, where is it going?

[Ken H.]

You know another (negative IMHO) thing about K&N’s that I hadn’t thought about before – Pooling of oil in the intake/air box. Gravity, intake suction, etc. Intake systems are designed to be dry. (Air humidity withstanding.) All that oil liquid and micro-droplets mucking about can’t be a good thing.

[FrankBrown]

Hey Frank,

 

Have you washed your RT???? It's Jim formerly of Florida, (black R1200R)now of Michigan.

 

As far as the K&N filter, I (should say Jay K.) replaced the OEM filter at 6k, now with 22K I checked it in preparation for the trip to Johnson City Tn. and found the filter to flithy!!! So much for the 50K miles interval.

 

Frank are you going to the BMW OA rally?

 

take care

 

jim

Hey Jim, yes I've cleaned it, three times. It's a very small filter, but you should get to 50k. No, not going.

[Selden]

Now that you've put that one to bed please start working on synthetic oil, ATTGATT and bacon intake vs. nutritional value.

There's a bacon intake system for BMW's? Sign me up!