Porsche’s most extreme Cayman model becomes even wilder with the Manthey upgrade from a lesser-known race team, enhancing its track capabilities and performance.
The Porsche Cayman GT4 RS Manthey might seem like a straightforward upgrade to the standard GT4 RS, but it’s more than just a performance kit. This modified version sacrifices any on-road comfort in pursuit of exceptional track times. While you may think the GT4 RS is the ultimate Cayman, the Manthey edition takes it to a whole new level.
Manthey Racing: The Performance Experts
Manthey Racing is not a household name, but it’s vital to the Porsche racing scene. Founded in the late 1990s, the German race team has been instrumental in running Porsche Motorsport’s GT teams. In 2013, Porsche took a controlling interest in Manthey. Since 2021, they have created aggressive performance kits designed for Porsche sports cars. Importantly, these kits are available through certified Porsche dealers, aiming solely to enhance track capability.
The GT4 RS serves as a remarkable foundation. Porsche intentionally designs the Cayman not to outshine the 911, and the GT4 RS comes closest to that line. The Cayman’s gas-powered version is nearing its end, prompting the GT Department to intensify their efforts in developing the GT4 RS. They even replaced the rear quarter windows with intakes to channel enough air to the 911’s flat-six engine. Compared to the standard GT4, the RS features a completely new drivetrain, stiffer body structure, larger brakes, and improved cooling. Essentially, it’s an entirely new car.
Enhancements from Manthey
While Manthey Racing leaves the powertrain alone, they focus on making the GT4 RS sharper in corners and more stable under braking. This is where the true value of the Manthey kit lies. It includes retuned aerodynamics for increased downforce, featuring a larger rear wing and carbon blades on the rear wheels. Additionally, the kit replaces Porsche’s Active Suspension Management system with manually adjustable coilovers.
These chassis and suspension upgrades compromise some of the road compliance the GT4 RS had. As a result, the Manthey version becomes a stiffer and more agile machine. This configuration might deter those looking for everyday driving comfort, but it is perfect for track enthusiasts.
Testing at Lime Rock Park
To see how the GT4 RS Manthey performs, we took the car to Lime Rock Park in northwest Connecticut. This track is renowned for its technical layout, measuring just 1.5 miles. Running the IMSA layout offers a balance of speed and challenge. While it bypasses the «Uphill» corner, it adds a demanding braking zone and a tricky chicane.
During initial laps, I found it hard to distinguish the Manthey-equipped car from the standard GT4 RS. Both models sound incredible, feel balanced, and provide strong, linear braking. The glorious induction noise is unchanged from the base model, which can be likened to riding a liter bike on the road. At first glance, the $53,946 Manthey package might not seem worth it.
Unveiling the True Changes
However, as I pushed the car harder, the real improvements became clear. Braking, which has seen modest hardware upgrades, is significantly better. On Lime Rock’s front straight, the standard GT4 RS felt nervous during threshold braking. In contrast, the Manthey kit provides stronger initial bite and more stability, likely due to the increased downforce.
Mid-corner, the Manthey kit maintains the car’s adjustability while adding a touch more understeer. Stiffer front springs and a rearward weight shift contribute to this effect. Yet, it still feels alive in the corners. This slight increase in predictability is key to achieving quicker lap times.
At Lime Rock’s double apex turn, Big Bend, patience is essential. The base GT4 RS can be challenging here. Previously, I found myself alternating between power and lift to get the car to rotate. The Manthey kit changes that, providing predictability and allowing me to apply power earlier on exit without worrying about losing grip.
Speed and Stability
As I tackled faster corners like West Bend and the intimidating Downhill, the increased downforce and high-speed stability became more apparent. I entered corners quicker, and my apex speeds rose as the aerodynamics inspired confidence. It’s likely faster than the standard GT4 RS.
To confirm, we fitted fresh tires to set a lap time. Over two runs, the Manthey-equipped car clocked 58.47 seconds, half a second quicker than the standard car from a year earlier. While half a second may not sound substantial, Lime Rock’s short length amplifies its significance. On longer tracks, this gap would likely widen. For example, the GT4 RS ran a 7:09.30 at the Nürburgring, while a Manthey kit-equipped version achieved 7:03.12, a six-second improvement.
Is It Worth It?
Ultimately, the answer to whether the Manthey upgrade is worth it depends on your goals. If you plan to take your GT4 RS to occasional track days for fun, you may not need the Manthey kit. However, if you are serious about lap times and performance, this kit is a smart investment.
For those who have no intention of tracking their GT4 RS but still want the prestige, Porsche offers the Manthey rear wheel aero disc for $680. It’s a tempting option for those who want to look good without the commitment to track driving.
