The main thing induction kits do is make more noise generally, however they can also affect performance, whether it's losing power which is possible, or gaining power which is often the desired reason an induction kit is wanted.
The performance increases of induction kits alone are often pretty limited unless replacing a poorly designed oe system, but even still they won't give you massive power increases.
i'd imagine the best way to get maximum power from induction would be an effective variable length intake manifold or similar, coupled with a reliable cold air feed and free flowing enclosed filter. as a fixed kit i'd imagine tends to only be at peak efficiency at certain RPM.