RML Group P39 prototype at Supercar Fest 2025

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.
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.