As the valves open, exhaust is free to flow through 3″ piping to an x-pipe that merges the exhaust flow for a higher pitched, smooth sound with maximum flow characteristics. With valves closed the exhaust is routed through secondary flow path piping and our unique muffler. The internal design has little to no restriction in the flow path, using straight-through perforated piping to allow exhaust gasses to escape and become muffled in the surrounding packing material of the muffler body. The muffler also incorporates an internal x-pipe to allow the exhaust flow to merge smoothly. All of these characteristics are crucial towards reducing and smoothing out the drone in the sub 3,000rpm range while enhancing the higher pitched note we were after under all conditions.
In addition to the bespoke muffler design, there are several other unique characteristics we’ve brought into play on this system which revolve around the secondary flow path entering the muffler. The key thing to note here is that the valves open flow path is not limited to the external x-pipe flow path as some of the exhaust flow is still going through the secondary flow path even when the valves are open. This design is essentially utilizing the entire secondary flow path through the muffler to smooth out the tone and drone in valves open mode as well. Utilizing this secondary flow path for cruising cabin presence, we were able to go aggressive on the design of the primary valves open flow path to maximize the sound improvement without incorporating additional resonators or mufflers. We also utilize a tip plate (same style as used on 991 GT3’s) allowing one to switch between tip assemblies/styles.
VALVES
The exhaust valves on this car have electronic actuators mounted to a free moving mechanical valve body. Factory exhaust valve programming has the valves closed until 4k rpm, then gradually opening from 4k-5k rpm at which point they are then fully open. With PSE on you can rev the car with valves open but as soon as you accelerate they close again and this cycle repeats with the same functionality to 4k with the progressive opening to 5k. For those looking for full valve override so the valves are 100% open at wide open throttle regardless of rpm, ECU tuning is available to achieve this as well as our tested and upcoming plug and play Valve Controller Kit.
SOUND
This system was designed to offer a more desirable sound experience with tone enhancement under all conditions. Enjoy more presence during casual driving and an aggressive wail summoned by your right foot. The blending of banks from the X pipes combined with the sound attenuating features of the muffler gives the car a higher pitched sound befitting of a GT car with a respectable increase in mechanical tone and aggression.
- A smooth experience in the cabin – from rolling on the gas at low rpm to high rpm WOT.
- Higher pitched, more refined, and more present character throughout the rpm range
- Comfortable with a reasonable level of cabin presence.
- With valves closed, volume is increased over OEM by a refined amount. The sound is not only more pronounced, but smoother and more exciting with more tone than the dull, hollow factory exhaust note.
- Moderately more aggressive at wide open throttle when valves begin opening at 4k then fully open at 5k. A gentleman’s OEM+ exhaust experience.
