As if the road-going Senna wasn't already extreme enough, McLaren is busy working on a hardcore, track-only GTR variant. After the McLaren Senna GTR debuted in concept form at this year's Geneva Motor Show, development of the production version is gaining traction. As dynamic testing begins, McLaren has confirmed some juicy technical specifications of its upcoming track weapon.

The biggest takeaway is that the Senna GTR generates a metric ton of downforce, although the automaker hasn't confirmed the speed at which this is achieved. The Senna's 4.0-liter twin-turbo V8 has also been tuned to deliver 816 hp, up from 789 hp in the road-going version. Torque output remains identical to the road car at 590 lb-ft.

The automaker has also released a sketch showing the Senna GTR's final production shape. According to McLaren, the track-only hypercar will be built on a chassis with a wider track and front and rear and center-lock wheels. The carbon fiber body will also have wider fenders, a larger front splitter and rear diffuser, and a repositioned active rear wing that's "coupled" to the rear diffuser to further improve the car's aero-efficiency, corning, and braking stability.

Since the Senna GTR doesn't need to meet road regulations, McLaren has stripped out the interior to the bare essentials by removing the airbags, infotainment central screen and folding driver display found in the road car to save extra weight. A new race-inspired steering wheel with integrated gearshift controls replaces the road-legal component. The only comfort feature that hasn't been removed from the road car is the air-conditioning to cool you down after intense track sessions. McLaren has also included a radar-assisted rear collision avoidance system as standard.

The car's weight hasn't been disclosed, but McLaren promises the GTR will weigh less than the road-going Senna, which tips the scales at 2,641 pounds. That also means it will have an even better power-to-weight ratio than the regular Senna. Production of the McLaren Senna GTR will be limited to 75 examples, each costing $1.4 million. Unsurprisingly, every example has already been sold.