LDH brings up a good point. One that I had always wondered about when seeing airbox dyno charts. But the same can be said for exhaust. Nobody ever goes and gets a bike with stock cans and a power commander tuned before they throw on a slip on and get that tuned. Sure they may pull a baseline with the stock exhaust and maybe the stock map from dyno jet, but it is the same situation. Inflated gains due to proper tuning on top of parts, and not just parts alone.
This is why you will never see an advertised "guaranteed" increase, only an "up to XXX more HP". All those maps you see on exhaust manufacturers websites and in magazines are after hours of tuning and fiddling to get the best numbers possible vs a stock off the floor bike.
Oh, and DK = Dan Kyle
I've actually given some thought to getting a map for the stock airbox, as i am not too sure how long I will keep the turn one box. I am planning on moving back to Seattle and am not as comfortable with an open style box in wet weather. I'm probably over thinking it though.