RML Group P39 hypercar prototype debuts at Supercar Fest

RML Group, the British engineering firm renowned for four decades of motorsport and engineering innovation, wowed spectators at Supercar Fest The Runway 2025 with the first public appearance of its limited-edition P39 hypercar prototype.

The event, based around top speed and repeated full-throttle acceleration runs, is staged annually at Sywell aerodrome, near Northampton. It provided the perfect opportunity for RML to show the car in public for the first time.  

Conceived to celebrate RML Group’s 40‑year milestone, the P39 transforms the already‑formidable Porsche 992.1 Turbo S platform into a hypercar that retains its daily usability with new, uncompromising circuit capability.

The next opportunities to see the P39 prototype run in the UK are at the Supercar Driver Secret Meet at Silverstone, June 17 and then the Silverstone Festival, August 22-24.

Aerodynamics: Active Intelligence Meets Supreme Downforce
From nose to tail, the P39’s bodywork has been re‑sculpted in carbon fibre and laced with active aero devices that completely recalibrate the Turbo S’s performance envelope. An electronically controlled rear wing hides its second element in Road mode, then elevates and pivots in Track mode to create a slot gap that boosts rear wing downforce by 24 percent. A driver‑selectable Drag‑Reduction System (DRS) can flatten the element, trimming drag by 23 percent for maximum velocity on straights.

Up front, an extending splitter slides 75 mm forward in Track mode, increasing surface area and moving the centre of pressure nose‑ward to sharpen turn‑in. Complementary airflow management – including air curtains around the front wheels, fender cut‑outs, an under‑body diffuser and vented rear arches – raises overall downforce from the Turbo S’s stock 1,432N to 5100N in Road mode and more than 6,500N in Track mode at 150 mph. These figures place the P39 firmly in competition with purpose‑built GT racers while preserving ride quality in road mode.

Chassis: Wider, Lower, Faster – Yet Remains Civilized
To exploit this newfound aerodynamic grip, RML engineers re‑imagined the chassis from the hubs inward. New suspension links widen the track, bespoke top mounts preserve ideal camber angles, and secondary springs increase wheel rates in Track mode without destroying ride quality on the road. Bespoke R53‑supplied dampers, tuned by RML, give the driver three cockpit‑selectable settings, while a four‑corner hydraulic lift system provides two rear and three front ride‑height options for everything from speed‑bumps to pit‑lane.

The anti‑roll hydraulics and rear‑wheel‑steer system have been recalibrated for the P39’s lower stance, wider track and longer wheelbase. Bespoke alloys – 20X10 inches up front, 21X12 inches at the rear – wear customer-specified tyres.

Powertrain: Three Personalities, One Huge Heart
Beneath the rear deck, the twin‑turbo flat‑six has been the subject of an exhaustive re‑engineering programme in partnership with Litchfield Motors. Larger‑diameter intake and exhaust plumbing, a unique Inconel exhaust valve – the largest ever fitted to a road‑going flat‑six – and optimised thermal routing lift output to 920 horsepower and 705 lb‑ft of torque in Sport/Sport + mode. Two additional presets give the powertrain dual personalities: a 600‑hp Wet mode for low‑grip conditions and 750‑hp Normal mode for fast road driving. All bespoke components carry a 12‑month/12,000‑mile warranty, while over‑the‑air diagnostics and calibration updates ensure the P39 evolves with its owner.

Leadership Perspective
Michael Mallock, Board Member responsible for RML’s Bespoke Division, comments:
“From the outset we set ourselves the challenge of building a car which could switch personalities at the touch of a button – serene on the road, savage on the circuit. The numbers speak for themselves, but what excites me most is how intuitive and confidence‑inspiring the P39 feels, whatever the setting.”

Paul Dickinson, Chief Executive Officer of RML Group, adds:
“P39 is a rolling demonstration of what RML’s Engineering Division can achieve. By integrating active aerodynamics, a re‑imagined chassis and a 920hp powertrain, we have created a hypercar that delivers relentless track performance yet remains perfectly at home on the King’s Road. It is the purest expression of 40 years of engineering excellence, distilled into a car that wears our badge with pride.”

Availability
The P39 will be built in a strictly limited run of 39 cars. First UK customer deliveries are scheduled for late summer 2025 following final tuning and validation testing. A full spectrum of bespoke options is available.

P39 Sales and aftercare agents have been appointed in the US and Europe.