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.

When introduced for the '05 model year, the C6 received the evolutionary Gen IV LS2 powerplant, which carried ratings of 400 horsepower and 400 lb-ft of torque. While the new engine's cylinder heads ...