Gixx1300R
Registered
When Modifying the Airbox you really should use a filter but there are no filters designed for this.So when I did the mods to my 96 GSXR 750's airbox,I made my own filter from 4 sheets of grey foam that is used for wall unit air conditioners.I bought a 12"X12" sheet of abs plastic and and sandwiched 4 sheets together and screwed them together.I then purchased small L breackets and bolted the filter inside the airbox.Lastly I used K&N filter oil on the foam.It worked great and cost only $15 total in supplies.Give it a try but make the filter before you modify the airbox to get the feel of it.