This short course develops an improved understanding of turbocharger performance and engine airflow for scavenging and emissions control. Turbochargers are highly effective for scavenging and controlling emissions for internal combustion engines. As an aerodynamic machine, changes in ambient conditions significantly influence the operating performance of turbochargers. Comparing the turbocharger operating conditions to performance maps requires precise data and a complete understanding of its usage. Utilizing this knowledge coupled with cylinder-port flow coefficients provides airflow prediction for engine performance and emissions control. This course provides an overview of recent technological advances in determining the effects of air inlet conditions on turbochargers controlling air inlet temperature, and measuring turbocharger performance. Also discussed are the heat transfer effects on turbocharger performance, and the influence of flow coefficients through the inlet and exhaust ports of large bore engines.