K&N Air Filter?

[oldfartracer]

What is everyones views on putting a K&N air filter on the ST? Pros. Cons?

[buckeyest1300]

There is a motorcycle mechanic in my area with a dyno. He says that a K&N filter actually drops the horsepower by 2 to 3 percent. That is not that big of a deal but don't believe the K&N advertisements that they will increase horsepower by 10%.

[dond]

Run........It's a K & N thread!!!! :eek:

[The Doktor]

I put a K+N air filter on my St1100, and it ran ****e!! never again. I tried various combinations of filter, filter with foam ring supplied, filter with oil, without oil etc..every way it ran bad.. Have the Honda filter back and its sweet.

[nm6r]

Dyno testing has shown a 6hp gain on the ST1300. The K&N even without any hp gain is obviously a lot for the money. It's re-usable and goes longer intervals between cleaning rather than replacing a stock air filter.

It is a different type of filtration media. There are some naysayers that don't know any better and think the more restrictive stock filter must filter better since you can't see through it at all. Once again, it's a different filtration media.

I have been in the swimming pool industry for 15 years. I compare the K&N filter to a Diatomaceous Earth filter and the stock filter to a cartridge filter. A DE filter is less restrictive but will filter 7 times finer than the cartridge and is capable of longer cycles between cleaning. The grids on the DE filter are not cleaning the water, they are merely a carrier to hold the DE. Same thing with the oil on the K&N. I'm not saying the K&N filters better than stock but it certainly isn't any worse and more air is always better.

BTW, I also had a K&N on my ST1100, no problems, ran great.

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif

[The Doktor]

Actually, one of the problems i had was not enough air. Found that the bike ran rich.. particularly when you would accelerate the bike couldnt cos it wasnt gettin the air..

[The Doktor]

anyone want a hardly used filter for a st1100??? lol

[sherob]

Dyno results from Motorcycle Daily on a ST1300 with K&N installed ;) I do not have one in my bike BTW :rolleyes:

http://www.motorcycledaily.com/21september04_kandnfilter.htm

[oldfartracer]

i'm not really looking for HP gains but in a thread I read about abrupt throttle pickup some people said that the K&N helped with this problem.

[tdeboeser]

I got one. For ease of use mostly. I wasn't lookin for HP gain, and I can't really tell if there is any. The intake sound is a little noticable, but I like that. I had one on my last bike ( SuperHawk ) without any issues - and the intake on that bike sounded sweet.

I thought my "abrupt throttle" was getting better. Either I was getting smoother or maybe ( problably not ) the K&N was helping. NOPE, I adjusted the CB and the "abruptness" came back - along with a much smoother running motor.

My $0.03 ( i'm a contractor :))

Tom de

[kingprawnokay]

I thought my "abrupt throttle" was getting better. Either I was getting smoother or maybe ( problably not ) the K&N was helping. NOPE, I adjusted the CB and the "abruptness" came back - along with a much smoother running motor.

+1 on the counterabalancers. I also enjoy the slightly louder intake noise...more like a sport bike.

[gene]

K+n's let in so much additional air if you don't increase fuel at same time as extra air IT WILL RUN WORSE.On carb bikes main jets will need to be increased a couple of sizes to prevent running lean which is a problem. Turbo Tom at Turbo city sells a new fuel preasure regulator that he will set based on your setup stock p.s.i. is 50# with k=n n my replacement came set at 60 # which mean a 20% increase in fuel. The St1300 injection can't and enough extra fuel to keep the proper ratio of fuel/air os it runs better with stock filter unless fuel is increased by preasure or larger injectors.

[tdeboeser]

Neither of my bikes have run noticably better or worse with a K&N... YMMV.


Tom de

[kingprawnokay]

K+n's let in so much additional air if you don't increase fuel at same time as extra air IT WILL RUN WORSE.On carb bikes main jets will need to be increased a couple of sizes to prevent running lean which is a problem. Turbo Tom at Turbo city sells a new fuel preasure regulator that he will set based on your setup stock p.s.i. is 50# with k=n n my replacement came set at 60 # which mean a 20% increase in fuel. The St1300 injection can't and enough extra fuel to keep the proper ratio of fuel/air os it runs better with stock filter unless fuel is increased by preasure or larger injectors.

This is simply not true. The ECM of any fuel injected bike should easily compensate for the addition of aftermarket pipes and a filter such as a K&N.

1. Another similar example of the flexibility of a bikes computer is change in altitude. If you're theory were true, than fuel injected bikes would not run well above a certain elevation.

2. My understanding of TT's fuel pressure regulator is that ST's typically run very lean. The regulator gives people the option of altering the stock fuel to air ratio without messing with the computer.

3. I'm with Tom. I haven't noticed a negative change in performance with the addition of 2Bros and a K&N. If anything, the bike runs a little smoother now.

[Highrider]

I currently use K&N's on my cars, primarily because they are built into a custom induction system. But I make sure they are oiled properly and keep up the maintenance. There are a lot of articles that report that along with the added air the K&N supply, they also let more dirt through. This has been documented in tests on fleet vehicles and verifying oil contamination levels.
The ST is fairly optimized for performance, and in good balance with reliability.
Since the ST1300 is such a great performer as is, I have elected to stay with the factory air filter and play it safe.

Dave
:biker:

[kingprawnokay]

Sorry. You're absolutely right. I wasn't thinking. Sorry Gene as well.

I forgot that all bikes don't feature a closed loop system (too much time around Honda cars). I shouldn't have made that mistake as my Z1000 doesn't have a closed loop system. The Zed's ECU intereprets specific engine info and makes adjustments to the fuel/air ratio accordingly without an oxygen sensor like Rocket's 'Busa.

Here's what I should have said. All bikes running a closed loop ECU system like the ST1300 will hold the air/fuel ratio at approximately 14.7:1 regardless of the aftermarket parts attached.

Once again, my appologies.

I think the 'Busa may now have a closed loop system. Most bikes will probably feature a closed loop ECU as emissions standards change.

[oldfartracer]

I picked the brain of the mechanic at my buddies shop and he's not a fan. He said in most cases he's seen the HP drop on their dyno after installing a K&N. I wasn't looking for HP gains but he didn't like other things about the K&N. I think I'll stick with the OEM filter. Thanks for your input.:bow1: