Gerhard Stefan and Philipp Göller transformed their passion for air-cooled Porsches into a thriving business, crafting €400,000–€600,000 custom “Apparatus” GS 964s—a unique piece of legacy for the modern car enthusiast.
From Father to Son
In the heart of Germany’s Black Forest, GS Manufaktur has become a global name in bespoke Porsche customization. Nestled in this affluent and storied region, famous for its lush forests, spa towns like Baden-Baden, and a deep-rooted tradition of German craftsmanship, GS Manufaktur was born as a dedicated arm of Gerhard Stefan’s longstanding workshop, Autohaus Stefan.
For decades, Gerhard operated independently, focusing on restoring and repairing cars with meticulous attention to detail. His dream of working with Porsches began when he purchased and restored his first 356 model 50 years ago—a car he still owns today.
By 2006, the workshop had turned its focus exclusively to air-cooled Porsches. But it wasn’t until 2017 that Gerhard’s son, Philipp Göller, joined him, taking the operation in an entirely new direction. What began as a father-and-son project to redesign a single Porsche 964 for personal use, unexpectedly turned into something much bigger. Their prototype, the GS1, garnered attention wherever they drove it, leading to requests for similar builds. By 2018, GS Manufaktur was officially established, creating the exclusive “Apparatus” GS 964—a modern reimagining of a Porsche classic.
At 74, Gerhard Stefan embodies decades of Porsche restoration expertise, serving as the backbone of GS Manufaktur. His son, Philipp Göller, credits his father’s profound technical skill while acknowledging their complementary roles. “My dad is the backbone of the operation—he’s the one with years of craftsmanship and technical knowledge,” Philipp explains. “I’m the one focused on the details, the modern technology, and managing the business day-to-day.”
Philipp’s journey to the family business wasn’t always obvious. Originally aspiring to be a Lufthansa pilot, Philipp had a passion for cars since childhood. “My first word was ‘auto,’ so in some ways, this was always meant to be,” he says with a smile. His early love of automobiles and a reassessment of his career path led him back to the family workshop, where he infused it with fresh ideas and modern aesthetics.
Together, they envisioned a car that combines the iconic aesthetics of the 1970s with the engineering advancements of the 1990s and today’s cutting-edge possibilities. This vision culminated in the creation of the “Apparatus” GS 964, a name inspired by a local term for intricate, masterfully crafted machinery—a fitting tribute to their handcrafted creations.
The Process: How the "Apparatus" Comes to Life
Each transformation begins with a carefully selected donor Porsche 964 from model years 1989 to 1993. Clients can provide their own vehicles, or GS Manufaktur can source one through their network. “Sometimes the donor cars come directly from our clients, and we help with the shipping. If they don’t have one, we can provide or acquire one for them,” Philipp explains.
While the initial condition of the donor car isn’t critical, as every vehicle undergoes a full frame-off restoration, a well-preserved car simplifies the process. “We are still using some parts from the original car, so while condition isn’t vital, a smoother start makes for a smoother process,” he adds.
The transformation begins with reimagining the car’s body. In the early days, Gerhard sculpted the panels by hand using clay molds. “That was the beginning of our journey to build our own design,” Philipp recalls. Today, those original shapes have been 3D-scanned and transitioned into precision-machined tools, enabling the production of high-end carbon fiber panels that replace parts of the car’s original steel bodywork. This innovation reduces weight while maintaining structural integrity.
Each “Apparatus” features over 300 bespoke parts, from CNC-milled ventilation grilles to custom spoilers, all designed and sourced in-house. “The lines my dad created are uniquely his; no one else could replicate them,” Philipp notes. “That’s part of what makes our work stand out.”
Roaring Engines and the Art of Bespoke Luxury
Under the hood, every engine is tailored to the client’s specifications. “We build everything from a standard 3.6-liter with 270 horsepower to a high-performance 4.0-liter system with 390 horsepower,” Philipp explains. Every engine is dyno-tested to ensure precision and optimal performance.
The suspension system is equally bespoke. While Bilstein’s B16 is the standard offering, GS Manufaktur also provides a fully custom MCS high-end suspension system for discerning drivers. Once assembly is complete, each car undergoes rigorous road testing, covering 500 to 1,000 kilometers to ensure all systems perform flawlessly. “We wait for the right conditions to test—everything from normal drives to high-speed autobahn runs,” Philipp says.
Inside the “Apparatus,” every element is fully customizable. Clients work closely with Philipp to design details like hand-painted instrument panels, bespoke leather upholstery, and luggage compartments fitted with custom sets. Exotic materials such as snake skin or camel hair are available, but always with an emphasis on maintaining functionality and design integrity.
“Ultimately, the client is king, but we won’t compromise our philosophy,” Philipp says. “We had one client who wanted to reinvent the car entirely, changing its concept. Even if the result might’ve been cool, we refused—it would’ve strayed too far from what the ‘Apparatus’ represents.”
Each car undergoes an extensive final assembly process, where every component is reviewed and adjusted to perfection. “We customize everything for each individual car,” Philipp says. “It’s more work, but it delivers the best results.”
“My dad taught me some traditional German values—quality, craftsmanship, and loyalty to our clients,” Philipp reflects. As he moves to the forefront of GS Manufaktur, Philipp is shaping the company’s future while honoring his father’s legacy—a legacy embodied in every “Apparatus” GS 964.
With decades of passion, experience, and innovation, GS Manufaktur remains a boutique operation, producing only five to eight cars annually. Yet, each is a timeless masterpiece, reflecting the personality and vision of its owner.
“We wanted to create something timeless,” Philipp says, “that reflects the client’s dream while staying true to our vision. For me, that’s what makes this all worthwhile.”
Website: https://www.gs-manufaktur.com/
In Profile: Philipp Göller
Philipp Göller is the co-founder of GS Manufaktur, a bespoke Porsche restoration and customization company based in Germany’s Black Forest. After initially pursuing a career as a Lufthansa pilot, he transitioned into the family business in 2017, working alongside his father, Gerhard Stefan, to develop the “Apparatus” GS 964, a high-end reimagining of the classic Porsche 964. Göller oversees the company’s business operations, design innovations, and modernization efforts, integrating advanced materials like carbon fiber and precision-engineered components into each build. Under his leadership, GS Manufaktur has expanded into a globally recognized brand, producing five to eight custom vehicles per year, each tailored to the individual specifications of its owner.
