They dont have recirc DVs as std so no need to worry there, but remove any DV fitted.

Removing the airbox then will give you SOME chatter, but TBH its not that loud (unlike S14s which chatter mega loud when you remove the std recirc DV).

But fitting a FMIC will make it chatter loads louder, as will fitting a metal filter-turbo pipe, and a Z32/Skyline type AFM which is much more free flowing.
As will more boost, more boost the better.

(Note, a different AFM cant be done without suitable chip/map)

And thats it from me, time to go drinking again...