Standard airbox is shit and restrictive. Car makes 280rwkw with the custom air intake I got, but with the standard airbox in it's own only made 270rwkw. I'll have my extra 10kw thanks. I got an intake setup that would pass you an EPA or a defect just because it looks like I have an airbox . If you wanna know it pm me
btw only talking about the standard r33 gtst airbox. Gtr ones are probably better hence you can make decent power with them withou being too restrictive.