The airbox is that size to create a large volume of 'still' air to improve the throttle response. I would have thought that if you were to increase the size of the entry to the airbox that it would help cancel out the effect of a smaller box but at the expense of more noise and possibly a detrimental effect to the jetting. Dynojet used to make jet kits for running without an airbox, the main feature was a smaller air corrector jet but you had to drill and tap to fit it because the stock carbs usually had a fixed orifice.
Thanks.
I e mailed dynojet about wanting to buy a kit to run cv carbs on my gpz500 without airbox, but they never replied. I have a second gpz now, so I can experiment a bit.
I'm also buzzed up about attempting to build an xbr engined 250rs.
