One of the power tricks people use on dirt bikes, snowmobiles, even diesel trucks is drilling holes in the airbox to let it breathe better.
Just make sure you drill on the right side of the filter.
I've seen air filter boxes with holes drilled on the clean side, so the air bypasses the filter entirely.
If you're going to drill holes in your airbox, do it on the dirty side, not the clean side.
Saw a guy lose his motor that way. Wild.