The exhaust architecture differs dramatically between the two 991 phases. For the 991.1, replacing factory manifolds with high-flow Exhaust Manifolds/Headers significantly improves scavenging and amplifies the raw naturally aspirated wail. For the twin-turbo 991.2, installing high-flow Exhaust Downpipes reduces turbo backpressure and increases spool efficiency. On both models, pairing these components with a valved or non-valved Cat-Back Exhausts system reduces vehicle mass and fundamentally alters the acoustic profile. We also supply Misc Exhaust Parts, including heavy-duty clamps and hardware required for correct fitment.