Porsche 911 GT3 Manthey Kit Narrows Downforce Gap to RS

The Manthey Kit has become a familiar proposition for Porsche GT owners seeking to further enhance circuit-performance without sacrificing their factory warranty. Developed jointly between Weissach and Manthey's Meuspath facility, the latest addition to the range targets the updated 992.2 GT3 with predictably obsessive results.

At 177mph in circuit mode, the kit generates a substantial 540kg of total downforce. Switch to road mode – the only setting legal for public use – and that figure drops to 355kg, still comfortably beyond what the standard car produces. Crucially, in order to meet type approval, the additional downforce comes without any increase in drag, meaning straight-line performance remains unaffected.

Porsche 911 GT3 Manthey Kit rear three-quarter view, showing rear wing and aero disc wheel covers

Achieving that balance required a complete rethink of the underbody. The turning vanes have been extended by a full metre to 1.5m, and a cover now seals the luggage compartment floor, creating a continuous aerodynamic surface from nose to tail. Up front, the splitter extends 12mm further forward, while new diffuser fins and side-mounted flaps increase front axle downforce. The swan-neck rear wing grows wider and gains a Gurney flap, with enlarged end plates curved inward to optimise airflow. Longer fins in the rear diffuser complete the package, working in concert with Manthey's signature carbon-fibre aero discs covering the rear wheels.

Underneath, Porsche and Manthey have developed a four-way adjustable coilover setup specifically for the kit, with compression and rebound adjustable without tools – encouraging trackside tinkering. Spring rates rise by 10 per cent at the front axle compared to the previous GT3 Manthey Kit, calibrated to exploit the increased aerodynamic load. Optional forged wheels in 20- and 21-inch sizes shed 6kg of unsprung mass.

Forged front wheel and PCCB brakes on the 911 GT3 Manthey Kit, with carbon side flaps visible

Twin exhausts and extended carbon rear diffuser on the 911 GT3 Manthey Kit

The braking upgrades are more restrained: braided steel lines come as standard, with racing-compound PCCB pads available as an option. The engine, gearbox, and differential remain untouched – which, given the 9,000rpm naturally aspirated flat-six needs no improvement, feels like the correct decision.

Reigning DTM champion Ayhancan Güven proved the point at the Nürburgring Nordschleife, posting a notary-certified 6:52.981 – some 2.76 seconds faster than the outgoing 992.1 GT3 with its own Manthey Kit. That time was set on Michelin Pilot Sport Cup 2 R tyres in less than ideal autumn conditions, with damp patches compromising grip at critical points around the 20.8km circuit. Manthey has already confirmed plans to return for another attempt in better weather.

Porsche 911 GT3 with Manthey Kit at the Nürburgring Nordschleife, white with black central stripe

For context, Jörg Bergmeister's lap in the GT3 RS Manthey stands at 6:49.328 – roughly three and a half seconds quicker. The gap may narrow when Güven gets a dry track, but the difference reflects the fundamental aerodynamic disparity between the two cars. The RS Manthey produces over 1,000kg of downforce; this kit generates half that figure.

That last point deserves emphasis. GT3 RS allocations remain notoriously difficult to secure, and while the GT3 Manthey stops short of giving those who missed out a workaround, the upgrades close the gap significantly.

The Manthey Kit will be available through Porsche Centres from March 2026. Pricing has yet to be confirmed, but expect a six-figure outlay once fitted.