Porsche's 992-generation 911 GT3 RS is already one of the most potent factory-built track cars anyone can buy, but Manthey-Racing is out to improve the formula with a range of performance upgrades.

Prototypes for the Manthey-enhanced 911 GT3 RS have been spotted testing at the Nürburgring, where Manthey's headquarters is located, and the first upgrades should be available by early next year.

Manthey is Porsche's most successful customer racing team, having won multiple races and championships. This success has earned Manthey the right to serve as Porsche's factory team on occasion, including in the World Endurance Championship, and it has also led to a range of Manthey upgrades being offered via Porsche showrooms.

The latest photos and video show Manthey testing a 911 GT3 RS with a much larger rear spoiler with an active function as well as a central stabilizer fin that connects the wing to a panel sitting where the rear windshield normally sits. Small vortex generators are mounted to the rear of the roof, and the rear diffuser has a new design. Manthey has also fitted its aero discs to the rear wheels of the latest prototype.

Most of the features are aimed at increasing downforce, particularly at the rear to help keep the car glued to the track surface when cornering. The stock 911 GT3 RS can already create as much as 1,895 pounds of downforce at 177 mph, twice as much as the previous 991-generation 911 GT3 RS, so Manthey has its work cut out for it.

For the previous 911 GT3 RS, Manthey upgrades also included a custom engine cover, adjustable coil-overs, custom brake pads, and custom brake lines, and many of these, and possibly more, should feature as part of the upgrades for the latest car.

Manthey upgrades are typically limited to the areas of aerodynamics, brakes, and suspension. This means the 911 GT3 RS's 4.0-liter flat-6 should still pump out a stock 518 hp, with drive sent to the rear wheels via a 7-speed dual-clutch automatic transmission. Despite peak power likely remaining unchanged, Manthey's work on the car should still reduce the stock 'Ring time of 6:49.328 by several seconds.

Manthey upgrades were finally made available to U.S. customers via Porsche earlier this year, starting with upgrades for the 911 GT3. This means there's a good chance the 911 GT3 RS upgrades will also be made available here.