True. Bikes like the RC-51, 929 and 954 all lost HP with a K&N swap.
The BMC Race filters will get you 1.5-2hp on the dyno in a 1000RR and save you 1.00lbs of weight.

In Europe, the "DNA" filters seem to offer simular gains.

However, like Deezhul points out, dyno numbers aren't everything, real world performance is all that matters.

I'l gladly take a bike that dyno's @ 135hp if it could pass you all on the street

 

i live and die by that rule.. I dont care if your bike makes 180whp and mine makes 165whp.. as long as i am ahead when my 6th gear limiter hits im happy. I have no interest in dynoing my bike. there is a dyno down here that notoriusly puts down big numbers.. i could care less what that sheet says!!

 

Good point Deezul,
I guess Im just trying to make up some power I lost with all the extra weight I gained with the swingarm and Im told that apinning that big wheel i have is also slowing me down wich im sure it does. Obviously I can launch now...and full throttle in 1st with no wheelies unless i clutch it, but I wnat to make the power back to make up for the added weight and Im not a big nos fan. I would however, REALY love to do a supercharger...especialy since mines kinda more of a straight line bike these days. I know you say you dont believe in dyno #'s but have you or anyone had it done? any gains? Ive heard not much gain in peak #'s but it will flatten out the curve a little. I had it done on my F4I, but I know the guy who did it was wayyyyy behind on dyno sesions and I think he just gave me a 5 min tune especialy since I could not tell a bit of diffrence when it was done.

 

having my 05 cbr 1000rr on the dyno with k&n and stock I did lose 1-2 hp. Actually the stock filters breath better but don't last as long check them frequently you'll be amazed what gets into your box. I still use the k&n cuase i do track days as often as i can. and they do filter smaller air particals. I just pull them out and wash them, in they go next track day good to go. BMC's are nice but let alot of stuff through and what goes through the filter ends up inside the motor.. In the end personal prefrence....

 

Just thought that I would bring this thread back to the top of the list and see just how many people have had issues with the K&N filters. I was considering purchasing the K&N filters, but if they don't fit then the BMG filters are worth the extra money.

 

the BMC are worth the extra money period
they fit better and give more horses you have to get the race version though
the street version flows the same as OEM

 

SAME DEAL i called k&n and spoke with a tech. he said just tighten down the screws on the air box and its fine. k&n work great with less room...what ever that means

 

or you can get a set that fits perfect without any extra wrenching

 

I opened my airbox just too se the state of my stock filters, and found out they were pretty clean at 6300 miles, except for a piece of wood just dancing in there!?, Anyway i took them out clean them with a rag a little bit, and removed the black plastics that go at the bottom opening on the filters, they look like they hold the filters in place, but after studying the airbox a bit i realized the filters aint going anywhere. I read at hooliganbiketech CBR site that those plastics (part #pp-md30) are restrictive to meet Epa restrictions, After that i went for a ride and it felt good, Have any of you guys have done this? My bike is stock, all i've done is the flapper mod.

 

BMC Race Filters. Get Some!