I've got an '05 F4i with a Yoshi full exhaust, PCIII, and a K & N. I just rode my friend's '98 F3 with just a V & H slip-on and there's not enough of a difference for the $$. I'm just glad that someone else spent the $1,100 or so and not me.

 

Ya, my '06 is completely stock, and I still ride the crap out of it. . .it's got plenty enough pull for me, and then some.
I guess I just figure that the factory knows what's best for my bike, so why mess with it? Well, the Harley guys say "loud pipes save lives" so maybe I should invest in a slip on. . .

 

the only reason why I like the k^nis due to the fact that its easier to clean and it dries so much faster. also, I feel that the filter needs to be cleaned less often. as far as performance; I think the bike got louder but I dont feel the extra kick. < my opinion alone.

 

When it comes right down to it, when your talking about how it breaths everything "piggybacks" itself and helps / improves one to anothers gains. IMO If I'm going to spend 400-500 for a slip on, I'd rather buy a system for 1000 and get the weight savings aswell, the weight helps more then in a straight line, i think it would be more noticeable in "turn-in" when cornering, andeven braking. Worst case scenariocan't notice it, trust me it will for sure improve you just don't notice it. I wouldn't replace the air filter just to replace it, but when it needs replacing, it'll be a free flow performance of some sort.

Hmmm, 600rr ... lets call it 100 rwhp for easy calculations, if you can add 20 hp (albeite not RWHP) your adding 15-20% respectfully. Oh and dropping 20 LB's, That to me sound like it would create an entirely different riding experiance. Also if you couldn't notice that kind of a change, I'm guessing it's because you weren't even close to using the bike in stock form to what it can do.

my .2

 

my stock 07 cbr 600 beat a 07 cbr 600 with full exhaust and dyno..k&n everything. makes no diff in my opinion

check out this fender emilinator kit thats now available

http://rover.ebay.com/rover/1/711-62...20156115442%09

I hope this link works..enjoy my friends