[old_skul]

I've seen Carrera guys take a hole saw to their airbox covers, in an attempt to get more air to the engine. I've also seen SC guys hack off the snorkel on their cover, leaving a large hole, and put a similar hole on the other end of the airbox.

Neither of these approaches do anything for power.

The exhaust on a 911 is where the bottleneck is. Adding more intake is not going to overcome where that constriction happens. In a Carrera, it's the muffer, cat, and exchangers - getting a free-flow muffler, a test pipe, and SSIs will improve power tremendously (20+hp). For an SC, it's the same thing.

Skip the intake. Hit the exhaust!