Modifying a Porsche is so forbidden that it has its own word, whispered within circles of folks who have swapped parts for higher-spec stuff. Those folks are called “outlaws.” But now it appears it’s more lax, given that there’s a new aftermarket performance kit for 992-generation 911 GT3s from Manthey Racing that’s sold through dealers and is even factory warrantied. It’s called the Manthey Performance Kit (MPK) and it costs $57,300 before you spring for the optional $15,500 lightweight forged wheels.
Nerds in the know will be well aware of Manthey Racing, which has a long career racing various models from the German automaker in sports car and endurance racing. Manthey has also gained recent notoriety by modifying Porsche GT road cars and breaking lap records. Manthey has done versions of the GT2 RS, 718 Cayman GT4, and 991-generation GT3 and GT3 RS, adding an “MR” at the end once the car has the full treatment.
And the treatment is comprehensive. Manthey twists every single knob it can just enough to fine-tune performance but not go nuts with power adders, widebody kits, or garish aero. Manthey doesn’t even add power, but they delicately refine and modify the suspension and aerodynamics of the already incredible standard cars.
In the case of the 992 GT3 performance kit that’s coming stateside, the MPK stiffens the front spring rates by 10% and the rear by 7% while replacing the factory adaptive suspension with motorsport-spec four-way adjustable suspension developed jointly with Porsche. It also refines the factory aerodynamics by adding a larger front lip and dive planes for more front downforce. Underneath the car, Manthey refined the factory air directors to extract more air from behind the front wheels to provide even more front downforce.
At the rear, the swan-neck factory wing element is replaced with a larger swan-neck wing with a gurney flap, adjustable angle of attack to fine-tune high-speed handling balance, and larger end plates to reduce drag. The fins of the rear diffuser are extended and made of carbon fiber. Finally, the distinctive Manthey aerodiscs installed on the rear wheels reduce drag.
All of these changes add up to a 4.19-second reduction in lap time around the Nürburgring. Over said 12-mile circuit, it’s very much a kit that saves hundredths of a second every corner rather than tenths or even full seconds a lap around most traditional road courses. $57,300 is a big pill to swallow for 4.19 seconds, though that doesn’t account for the subjective driving feel the kit might provide.
Nonetheless, this is a rare time when you can modify a Porsche through a dealer with a factory warranty. It costs a lot of money, but there is a big cool factor to factory-supported racing parts and the huge adjustability the kit provides. But I think I’d spend that money on a Subaru BRZ and a whole lot of driver coaching.