Last week I wrote a post saying that my new2 brothers slip on and K and N air filter weren't making a difference. I formally retract my statements. After putting the stock pipe back onto my 05 F4i I could tell the difference in the performance. The bike seemed slow and heavy. Also, I had the pipe on incorrectley, it was touching the swing arm which made the bike vibrate, and the pie sound louder. Please forgive me almighty Cbr posters for ever doubting your collective wisdom. Now all I need now is a power commander, and I'll be ready to take on Nicky Hayden!! [:-]

 

PC3 and a custom map and you'll be zoo00mmin'

 

Thanks for the info. The PC III is the thing that will make a difference.

 

I had a K&N on my bike last year, but took it off after a couple weeks.
Didn't really notice a difference.

Yes it'll flow a little more air than the stock filter, but then I read a good post on here. Basically it said that the factory filters have that little lip on them.....that's there to keep turbulence down in the airbox so the air can flow smoothly into the throttle bodies. Some guy/Honda designed it for a reason...u know???
The K&N filter doesn't have and therefore doesn't prevent the turbulence.

So I took mine out & sold it and just stuck with the factory filters.

But if you're happy with it....great! Just my 2 cents though

 

Good to hear you like your pipe, one difference I did notice is that it is lighter in weight, and I love the sound of the rumble when your ripping through the gears at 10K

 

Prefer foam filters myself-much easier to clean/maintain--guess my off road roots comin out again