Redeveloping the SOUL 718 4.0 Exhaust Systems

By installing the naturally-aspirated 4.0-liter flat-six into the 718 platform, Porsche signaled a continuing commitment to the emotional powertrains that defined its sports cars for generations. Long-time Porsche enthusiasts, frankly, knew nothing else from Stuttgart.

The GTS 4.0 and GT4/Spyder models were hotly anticipated and remain highly sought after for both collectors and spirited drivers, the latter of which often yearn to elevate that sensational experience. Our full suite of exhaust components can upgrade that experience incrementally or transformationally, with three sections of the system available to swap individually: headers, over axle pipes and the rear muffler.

Each section offers specific potential for sound and performance to meet a customer’s goals. Some drivers are looking to squeeze out a few more tenths on the track, while others just want to enhance that weekend morning drive. But our search for the ideal driving experience never ends and we’re always receptive to feedback from those customers, which motivated us to revisit our 718 4-liter product portfolio to continue its development.

Our initial goals upon introduction to the market in 2020 were to produce a higher, smoother pitch and more refined tone quality akin to the motorsports flat-sixes that enthusiasts fell in love with. But for most drivers, there’s more to it than that, and a valved system couldn’t rely on thrill alone and needed to provide a reasonable cabin presence and a tangible difference in sound level when asked upon.

To achieve the dynamic sound that everyday drivers were looking for, our R&D team tested countless variations of resonators, mufflers, and other technology to narrow in on a sweet spot with both valves open and closed. Once we dialed in that combination, it was obvious and it felt groundbreaking—and our customers initially agreed.

But in the years since, we along with our competitors have advanced exhaust technology and production and used that experience to deliver better and more thrilling products. We’ve stockpiled an arsenal of anti-drone knowledge, highlighted by our solutions for the new GT4 RS. Upon the arrival of Porsche’s new road racer, we planned to implement similar methods for the exhaust, but it proved to be an entirely different animal. We couldn’t do a simple test drive without being rattled by drone. We had no choice but to get creative in addressing it.

Intricate and efficiently-designed anti-drone tubes allowed us to significantly reduce resonance while fitting the exhaust package into the envelope the car provided us. A muffler, full 3-inch tubing and anti-drone technology was a lot to implement, and was all necessary. There were no corners to cut. While that gave our R&D team a massive headache, the lessons we learned were invaluable.

Satisfied with the results of that project, and now much further in the timeline of anti-drone technology, we fitted those applications toward the standard 4-liter cars with ultimate satisfaction. We don’t give credence to decibel numbers, only their effective and perceived deltas, and the difference is dramatic. We confidently claim that cabin presence has been reduced to the levels of the stock exhaust with valves closed yet it still possesses the theatrical potential with valves open, especially paired with a set of Over Axle Pipes in our Sport Package.

In addition to our evolution of the Valved Exhaust System, our work in creating a reasonable Race Exhaust for street use for the GT4 RS gave us the pathway to do the same for the standard 4-liter cars. For many, the Race Exhaust is exactly what they want it to be; but for others, they’re making a compromise. They trade low-RPM resonance for intoxicating tone wide open, but we thought we could bridge that gap with what we’d learned over the years.

Our unique drone canister design reduced the GT4 RS’ excessive drone to a reasonable level and would almost certainly deliver those results to the RS’ little brother. We were right. Calling it a night-and-day difference is hardly hyperbolic, even if it’s not a stand-in for a proper muffler. But it can help take the edge off for enthusiast drivers in dynamic situations and can be installed as a modular upgrade to existing systems.

Ultimately, drivers are craving the signature sound of that naturally-aspirated flat-six, and that’s much of why Porsche made the car for them. We made the exhaust for them too, whether they want more, or way more, or somewhere in between. We’re always listening.