When you guys say "illegal", you are referring to it's roadworthiness...

The question i assume is "is it legal for a p-plater?"
I am assuming that if the law is the same as Vic, then it states no performance enhancing engine mods... I leave the interpretation open on that, but i would say don't tempt them, coz you will get done for anything nowadays and the fines are HUGE.
I would look into a K&N replacement filter element for a bit more breathability!