DEVELOPMENT: Before Porsche began implementing valved exhausts into the Turbo 911s, they were known for their muted exhaust note, to meet customer expectations on cabin sound and European sound regulations. Our goal in developing the 991 Turbo Valved Exhaust System was to create the ultimate solution for enthusiasts seeking precision sound control and enhanced performance. Our system features a meticulously engineered dual-path design. When the valves are closed it creates a quiet yet rich experience, ideal for low-profile cruising or adhering to strict track sound limits. Opening the valves unlocks a larger 3″ primary flow path, maximizing performance while producing a bold tone.
The factory exhaust design presents limited space for incorporating a muffler into the secondary flow path. Simply reducing tubing diameter to manage sound levels would have a minimal impact, so we took a more innovative approach. We start our secondary flow path with smaller piping which flows into oversized resonators. These resonators work in harmony to significantly suppress sound levels, smooth out unwanted drone, and cancel exhaust pulses, resulting in a subdued and refined exhaust note at low RPMs. Despite the reduced sound levels in this configuration, the overall flow is still improved over the factory muffler, delivering a seamless blend of enhanced performance and discreet operation. When it’s time to turn up the theatrics, the system’s engaging sound profile is just a switch away.
To ensure a tangible delta between valves open and valves closed, we deviated from our traditional blended x-pipe design as we found that didn’t provide enough volume when combined with a secondary flow path. After numerous prototypes and revisions, we opted for a tuned length primary flow path blended with a balance pipe. This design allows for a more noticeable sound difference between valves closed and valves open. Compared to a GT2 RS style dump pipe (direct from cat to the bumper) this offers a much more refined tone and less mechanical sound from the valves operating.
In the end our product matched all of the parameters we were seeking:
- A noticeable difference between valves closed and valves open
- A comfortable and quiet valves closed experience
- An aggressive yet refined valves open experience
CONSTRUCTION: Each system is assembled in-house out of thick wall .065″ T304L stainless steel and rigorously quality checked.
BOLT ON AND GO: Each product is tested in a fixture to ensure perfect fitment then foam packed to ensure it arrives in perfect condition with all necessary hardware for installation. This system can be configured to work directly with your car’s Homelink buttons.
