I finally just fitted my hooked airbox today, I am guessing you leave out the collector and
a little more air would get in.
However without the collector to direct up into the top of the tank, most of the air would be wasted being displaced lower down, therefore not being utilised correctly???
To me it looks like 1/2 would flow under hookeds plate and into the engine........
Not on mine, opens at around 4 inches or so.......
If yours is 1 inch, thats a good chance its the restricted type. Should be easy
to remove that part and fit back, leaving you with the proper 4" opening.