A proper cold air intake will provide very minimal performance gains over stock. But in the search for power, the intake is the first limiting factor you encounter and need to overcome. As you build things further down the line, the performance increase is helped along with a proper CAI. Things like larger TBs, ported upper and lower manifolds, headers/TPs/HFCs, and exhaust can all combine to increase N/A power.
I did my first CAI for looks. It was a little less efficient than the stock intakes, which are pretty efficient, frankly. The R2C CAI with black chrome metal (
) with filters in the engine bay accompanied by a heat shield that sealed well to the hood. The metal tubes were killer on AITs though.
I am converting the car to a track/autoX vehicle, so I've got a proper CAI to install - aFe Takeda Attack Stage-2 with filter in the front bumper opening (like Stillen Gen3s, commonly considered the best N/A intake for the 370Z)