The KawaTurbo has a complex intake-air system, this is probably the reason why at Kawasaki they were developing an air funnel to scoop air in the turbo.
It works very well until 130 HP, then it´s restricting air flow.
And it is probably the reason why a lot of people use a K&N filter.
It seems to go well even with a bit of water.
But i´m afraid placing an open pod filter behind my frontwheel, living in the Netherlands is somewhat asking for trouble with 200 annual raindays ;)