I want to keep my stock airbox and I'm keen to replace the top half of my R33 GTST's airbox and the scoop / funnel / snorkel type thing that feeds it from the front of the engine bay with something made of the same material but larger. I'm getting a side fed (Blitz LM or similar) FMIC, so space/placement isn't a problem. I've seen direct replacements for other cars which literally just widen/open up the mouth that feeds the top of the airbox so you get more air.
If I can't find an off the shelf product (haven't seen one yet), I might have to buy someone's spare and try changing it into the shape I want (although I dunno how I'd do that, and I'd need spare plastic to do it cos the end result would be larger than stock). I'll have a solid metal pipe from AFM > turbo, so no worries about that sucking closed.
I've seen the Blitz airbox cover replacement thing and it's not what I'm after, it takes air from inside the engine, unless you create some kind of extra air guide which would have to mate up with the underside of the bonnet. The ARC induction kit is also not what I'm after for a similar reason. I also don't mean the ones which replace you're airbox-side headlight, or sit in the gap between your headlights. BTW, I have a stock bonnet and don't intend to cut into it.
I'm not really worried about appearance, mostly concerned about only taking air from the same region the stock box does, and increasing that area.
Thanks in advance for any suggestions. I'd also welcome recommendations of fabrication places that can (better yet, already HAVE) manufactured the kind of thing I'm talking about, and can be sure it would fit etc.