Well, yeah, the FI SV automatically adjusts (to a point, after which an aftermarket computer, i.e., power commander; is necesary.). I don't know about the carbed ones. I am not familiar with how much of an effect the K&N has on the intake and whether or not jetting it would be necessary.
But if you're looking for an aftermarket exhaust to squeeze out that extra two or three horsepower (I've never had it dyno'd or seen definitive numbers so I can't be sure), I would venture to say it would behoove you to invest in the $45 filter to complement the exhaust. But... to each his own.
Beyond personal pride of having the extra two horsepower, however, it really won't make that much difference in your daily riding (unless you're on a track
maybe or struggling to get that extra 1/10 of a second out of your ride to work.:P
That said, however, many little changes do make a difference in the long run. So it's basically your preference. I'm not sure what you mean by "all that," but, as far as air filters go (which isn't far, I guess
), they are pretty much the as good as they come. (Not to say others may not be as good, but they are as good as, if not better than, most.) But were talking air filters here so...
BTW, balance
IS key, as Northwind said. In and out must be proportionate. When I said air is predominate, I simply meant you use a larger
VOLUME of air compared to the volume of fuel. That does not mean boost the air and let your bike sputter and putter around in the misery of leaness. [/b]