This 920-HP Carbon-Bodied Porsche 911 Left Jay Leno Seriously ImpressedGuessing HeadlightsAndre NalinTue, September 15, 2026 at 8:00 PM UTCAdd us on GoogleImage Credit: Jay Leno's Garage / YouTube.Jay Leno has driven enough modified Porsches to know that extracting huge power from a 911 isn't particularly unusual anymore. Building one that fundamentally changes what a 992 Turbo S can do without ruining the qualities that make it such an effective road car is a tougher assignment.That's the challenge British engineering company RML Group set itself with the P39 40SE, also known as the GT Hypercar. The heavily reworked 911 recently arrived at Jay Leno's Garage, where RML CEO Paul Dickinson explained exactly what went into creating it.RML started with a Porsche 992.1 Turbo S, stripped away its exterior, and approached the project much like it would a motorsport program. The company's ambition was to fill the gap between the everyday usability of a Turbo S and the track-focused character of a GT3 RS.AdvertisementAdvertisementLeno eventually took the finished car onto the road to find out whether that combination actually works. Considering this particular 911 produces 920 horsepower and wears an entirely new carbon-fiber body, RML certainly didn't take the easy route.This Isn't A Porsche With A Body KitImage Credit: Jay Leno's Garage / YouTube.RML scanned a stripped Turbo S and created a digital model before developing the new body using computational fluid dynamics and chassis simulation. There were no clay models, with the company moving directly from digital development toward production tooling.Almost the entire exterior is carbon fiber. From the A-pillars rearward, the main body is effectively one large carbon structure, while another section forms the front, with the doors and other components completing the transformation.The design was inspired by the question of what a modern Porsche GT1 might look like. Its roof scoop feeds air to the engine, while the enlarged body, vents, flat floor, huge diffuser, and active aerodynamic components were designed around function rather than appearance alone.AdvertisementAdvertisementIn its normal configuration, Dickinson says the P39 produces roughly three times the downforce of the Turbo S. Track mode deploys additional aero for another 15–20% of downforce, while a drag-reduction setting opens the rear wing on straights.The Flat-Six Now Makes 920 HPRML didn't need to completely rebuild Porsche's 3.8-liter twin-turbo flat-six to reach its target. Instead, specialist Litchfield modifies supporting hardware, including the turbochargers and intercoolers, while improving airflow and recalibrating the engine.Output rises from roughly 650 hp to 920 hp. The Porsche eight-speed PDK and factory carbon-ceramic brakes remain because RML concluded both were already capable of handling the additional performance.The suspension receives considerably greater attention. Hydraulic controls provide multiple ride heights and adjustable damping, while the track has been widened by 100 mm through properly re-engineered suspension rather than simple wheel spacers.Jay Leno Reckons RML Found The BalanceImage Credit: Jay Leno's Garage / YouTube.On the road, the P39 initially impressed Leno by behaving surprisingly like the Turbo S underneath it. The cabin remained comfortable enough for conversation, and RML intentionally preserved much of the familiar Porsche interior.AdvertisementAdvertisementSwitching into Sport Plus revealed another side. Leno praised its precise steering, sharp response, and dramatically more aggressive character once the full performance settings were engaged.His conclusion was close to exactly what RML hoped to achieve. Leno described it as feeling like the "perfect balance" between a road-going Porsche and the GT3, while noting that bumps didn't deliver the punishment he associates with the more track-focused car.Only 40 Will ExistImage Credit: Jay Leno's Garage / YouTube.RML plans to produce 39 customer examples plus its development car, giving the project a total of 40 cars in recognition of the company's 40th anniversary. Each conversion takes roughly 20 weeks, with customers supplying a compatible 992.1 Turbo S donor.For American buyers, the P39 40SE is being offered through Graham Rahal Performance. RML says production is currently moving at roughly one completed car per month.AdvertisementAdvertisementPlenty of companies can make a 911 faster. RML's trick is trying to make a Turbo S substantially more extreme without making its owner regret driving it to the track.If you want more stories like this, follow Guessing Headlights on Yahoo so you don't miss what's coming next.
