The Porsche 911 GT3 Cup MR 30 gives Manthey’s 30th anniversary something more useful than commemorative stitching: a 4.2-liter flat-six producing 560 PS, approximately 552 horsepower, backed by substantial cooling, aerodynamic and suspension changes.
Unveiled on October 9, 2026, alongside the 718 Cayman GT4 RS Clubsport MR 30, the new model is limited to 15 examples. Manthey will also build 15 Caymans, completing a 30-car anniversary collection. These are competition vehicles, so buyers should not confuse either model with a road-going Porsche wearing a Manthey performance kit. www.manthey-racing.com
The interesting part is how differently Manthey approached the two cars. The 911 gains displacement. The Cayman concentrates on extracting more from its existing package.
Both approaches have considerably more engineering behind them than changing the paint and calling the result exclusive.
The Porsche 911 GT3 Cup MR 30 Starts With a Bigger Engine
Manthey bases the Cup MR 30 on the 992.1-generation 911 GT3 Cup, increasing engine displacement to 4.2 liters. Its naturally aspirated flat-six sends power to the rear wheels through a six-speed sequential gearbox.
The official Manthey announcement specifies 560 PS and 412 kW. That converts to approximately 552 mechanical horsepower, rather than 560 hp. www.manthey-racing.com
The distinction is small enough to disappear in casual conversation, but it belongs in a specifications table. Metric horsepower and mechanical horsepower use different definitions.
More displacement can increase an engine’s air-processing capacity, but the final result still depends on breathing, combustion, calibration and operating speed. Manthey’s published announcement does not provide enough internal-engine detail to identify a specific bore-and-stroke combination or reconstruct the modification.
What it does establish is that the larger engine forms part of a broader vehicle development program.
Cooling Gets as Much Attention as Horsepower
The Cup MR 30 uses a central radiator arrangement and enlarged brake-cooling inlets. Manthey says the radiator layout improves airflow management while reducing vulnerability to contact damage, and the brake ducts reduce thermal loading. www.manthey-racing.com
Those changes matter because a race car must maintain performance after its opening lap.
Engine heat rejection, brake temperature and aerodynamic balance interact. A larger cooling opening can move more air, but it also affects drag and the airflow passing around the vehicle. Engineers must manage where the air enters, how it passes through the heat exchanger and where it exits.
Brake cooling creates a similar balancing act. The goal is to keep components within a useful operating window throughout a stint.
For a street car attending track days, the lesson is practical: inspect the complete brake system before assuming a more expensive fluid will solve every heat problem. Our Best Brake Fluid for Track Days guide explains how fluid, pads, rotors and cooling work together.
Horsepower gets the photograph. Cooling helps the car remain available for the next one.
Wider Tracks and Adjustable Suspension Support the Engine
According to Speedweek’s technical coverage, the 911’s revisions include wider tracks—20 millimeters at the front and 50 millimeters at the rear—along with six-way adjustable coilover suspension and revised axle kinematics.
Manthey also develops the aerodynamic package around a revised splitter, underbody treatment and rear wing. www.speedweek.com
Those changes deserve attention alongside the engine.
Track width and suspension geometry influence how the tires respond to cornering loads. Damper adjustment provides additional control over vehicle movement, but more adjustment also creates more opportunities to get the setup wrong.
Aerodynamic loading adds another variable because its contribution changes with speed. A suspension setup must accommodate both mechanical grip and the loads generated by the bodywork.
That is why copying a race car’s visible parts onto a street build rarely reproduces its behavior. The components work as a coordinated system.
The Cayman MR 30 Takes a Different Route
The 718 Cayman GT4 RS Clubsport MR 30 retains its 500-PS flat-six—approximately 493 hp. Manthey instead focuses on lighter components, revised aerodynamics and cooling.
Carbon-fiber bodywork and a lightweight wheel package reduce weight by a combined 5.7 kilograms, approximately 12.6 pounds, compared with the base model. The Cayman also receives central radiator treatment and brake-cooling development. www.speedweek.com
| Specification | 911 GT3 Cup MR 30 | 718 Cayman GT4 RS Clubsport MR 30 |
|---|---|---|
| Engine | 4.2-liter naturally aspirated flat-six | Naturally aspirated flat-six |
| Published power | 560 PS / 412 kW | 500 PS |
| Approximate horsepower | 552 hp | 493 hp |
| Main development focus | Displacement, cooling, aero and chassis | Weight, cooling and aero |
| Production | 15 cars | 15 cars |
| Planned deliveries | First quarter of 2027 | Beginning November 2026 |
Source: Manthey’s technical announcement. www.manthey-racing.com
The Cayman’s weight reduction is modest in absolute terms. Its value should be assessed alongside component location, airflow improvements and the rest of the package.
The useful takeaway for enthusiasts is the development method: identify the limitation, then address it. More power is one possible answer. Consistent temperatures, better balance and improved tire control can be equally worthwhile.
When selecting parts through Pro Street Online, build around the demands of your vehicle and how you use it. A coherent brake, tire and suspension combination usually makes more sense than collecting unrelated upgrades.
The Nürburgring Number Needs Context
Manthey reports that an earlier, lower-powered development version of the 911 package recorded 7:58.605 on the 24.358-kilometer NLS configuration.
That is a manufacturer-reported development result. It is not an independent test of the finished Cup MR 30, and it should not be compared directly with lap times recorded on shorter Nürburgring layouts. www.speedweek.com
Track configuration, conditions, tires and vehicle specification all affect a lap-time comparison.
Removing those details produces an excellent argument online and a poor engineering conclusion.
Orders Close October 30
Manthey will accept purchase requests until October 30, 2026, then allocate the limited production run. Cayman deliveries are scheduled to begin in November, with the 911 following in the first quarter of 2027. www.manthey-racing.com
Car and Driver reports U.S. prices of $580,000 for the 911 and $390,000 for the Cayman. Buyers should confirm the applicable specification, charges and allocation terms directly with the seller. www.caranddriver.com
Most Pro Street readers will never order either car. Their development still offers a relevant lesson: performance comes from making the engine, cooling, chassis and aerodynamics support one another.
Manthey has added anniversary details to that work. Fortunately, it remembered to do the work first.
