The original (OE) Stinger exhaust is designed to meet worldwide noise regulations, but for enthusiasts it is too quiet - Luxury not Sport.
The OE exhaust contains sprung-loaded flap valves within each rear silencer. These completely block all exhaust flow until the gas pressure is sufficient to open them.
Kia’s clever engineers had good reason to include this unusual feature but that reason cannot include exhaust efficiency. Normally aspirated race engines require calculated exhaust gas back-pressure but turbochargers require the least possible resistance, to allow the turbos to spool up to 80,000 rpm as quickly as possible.
We also offer secondary catalyst delete pipes (pictured above). We recommend installing both our Sport system and these 'decat' pipes to maximise the experience and offer optimal flow.
QuickSilver’s Sports Exhaust gives boost from lower rpm that comes on more suddenly. So, in practice (overtaking for example) the throttle response is noticeably improved.
However, most Stinger owners will enjoy the QuickSilver Exhaust for the reduced weight and, especially, the enhanced soundtrack. A lovely smooth V6 note that howls when asked.... without spoiling the luxury.