The 991 generation represents a major turning point for the 911 Carrera line. While the 991.1 utilises a naturally aspirated 3.8-litre engine where forced induction hardware is inapplicable, the 991.2 Carrera S and GTS employ a twin-turbocharged 3.0-litre flat-six. Managing boost pressure accurately on the 991.2 is critical when increasing engine output. Upgrading the factory pressure release mechanisms with high-performance diverter valves prevents boost leaks, eliminates damaging compressor surge, and ensures crisp throttle response during rapid PDK or manual gear changes.