Theon Design has unveiled its latest commission based on the Porsche 911 (964), re-engineered from a Carrera 4 donor into a lightweight, rear-wheel-drive configuration.
The build centres on a naturally aspirated 3.8-litre air-cooled flat-six producing 407bhp and 303lb ft of torque. Power is delivered through a rebuilt five-speed manual gearbox, with the original four-wheel-drive system removed in favour of Carrera 2 specification.
Weight reduction is a key aspect of the project, with the car shedding approximately 325kg compared with the donor vehicle. The resulting wet weight is quoted at 1150kg, equating to a power-to-weight ratio of 354bhp per tonne. The body is constructed largely from carbonfibre, although steel doors have been retained.
According to Theon, this decision was made to preserve the closing characteristics associated with original 911 models. A bespoke carbonfibre ducktail, inspired by the 2.7 RS, has been developed specifically for the car, while exposed carbon weave is visible in selected areas beneath satin lacquer finishes.
Suspension is provided by a TracTive semi-active system, combined with a front axle-lift function to improve usability. The car runs on Michelin Pilot Sport 4 tyres and is equipped with RS-specification brakes painted red. The car’s exterior finish is a bespoke paint-to-sample colour created by combining two historic Porsche shades, Nato Olive Green and Underberg.
Additional detailing includes ghosted stripes, champagne-finished trim and 18-inch Fuchs-style alloy wheels. In the engine bay, carbonfibre components are complemented by a champagne-finished plenum sourced from a Porsche 911 GT3 (997), along with a matching engine fan. The exhaust system features a switchable valve, operating automatically under load or manually via driver control.
The interior structure is constructed from carbonfibre and trimmed in Liquorice and Saddle Brown leather. Recaro CS front seats are upholstered in Pepita cloth, referencing classic Porsche design, while incorporating updated materials used in later models such as the 991 Sport Classic.
A machined-aluminium dashboard forms the centrepiece of the cabin, with additional metal detailing applied to controls and trim elements. Technology has been kept to a minimum, with a Bluetooth-only audio system paired to a Focal amplifier and speakers, and USB-C ports integrated discreetly.
Each Theon commission is developed in collaboration with the client and requires approximately 6000 hours of labour, with build times of around 18 months. Prices for Theon Design builds start from £430,000, excluding donor vehicle, shipping and taxes.
More details are available here.
