Bolting on an aftermarket intake manifold has long been the introduction to hands-on hot rodding. Improved looks, performance, and, often, fuel economy can be just an intake swap away. Not to mention ...

Your intake manifold. It takes in air and sends it to your engine's combustion chamber. This is basically the start of the combustion process. After all, you can't have combustion without air.

Last month we showed what gains were available from three aftermarket Three-Valve intake manifolds in naturally aspirated trim. This month we're going to try the same three intakes, only now we'll see ...