It's an interesting idea to use the airbox as a chamber. I guess what you are doing is isolating the filter (which is always a bit restrictive) and hoping that the air is still enough in the box that the intake virtually starts where the intake tube enters the airbox. Kind of like a short ram air intake with pre ducting.
What I'd be tempted to do is add a ram tube at this point, hopefully smoothing the airflow from the airbox to the TB and try to alleviate swirling at that point.
I've had a lot of experience dyno tuning motorcycles, and one thing that always stuck out was that using a large a volume of airbox (they are actually 'still air boxes'- to create a pool of air as free of swirling) as possible is always beneficial to driveability as far as power characteristcs are concerned. Take the airbox out and low to midrange always suffers at the expense of top end power, (which rarely gets used outside of drag racing).
So your idea may just work.
I'd be interested to hear the results for sure.
On another note I've decided to go the SRI route, as pictured here.
I like the stock rubber intake because of the increasing diameter, and also because it's rubber, which is a much worse conductor of heat than metal. I'll use a filter as pictured with a built in ram tube such as a Blox filter.
I'm inclined to leave the stock resonator and piping in place in the hope that it provides some cool air and perhaps play with some heat shielding.
I haven't pulled the intake tube off yet to measure it to get a filter set up , but the diameter where it fits onto the airbox looks to be at least 3 1/2 inches.
I notice Matt said he fitted a filter with a 3 inch inlet, but this looks too small for my inlet. I'd be inclined to go for a 3 1/2 inch filter ram tube combo.
Has anyone done this?