Because a turbocharger needs the exhaust to work ... For air to get to the engine in the first place, the throttle valve must be open. You control the throttle valve with the accelerator pedal.

elimination of the throttle valve and its pumping losses, in-cylinder exhaust-gas recirculation—to novel ideas such as divided exhaust ports (DEP). These route the flow from half the exhaust ...

Thanks to OEM-developed variable valve timing (VVT), it ... Chrysler varies the exhaust lobe independently to improve idle and part-throttle combustion stability with the relatively big cam.