A year after its debut in concept form, the McLaren Senna GTR has been revealed in final production specification. “Production” is, of course, a word that doesn’t quite apply to the Senna GTR since we’re talking about a track-exclusive hypercar here.

McLaren says the Senna GTR is “the quickest track McLaren outside of Formula 1,” and that should tell you all you need to know about it. It’s powered by a 4.0-liter twin-turbocharged V8 engine that produces 825 PS (814 hp) and 800 Nm (590 lb-ft) of torque.

That means it has 25 horses more than the road-going Senna. Engineers extracted those just by engine control recalibration and removing the secondary catalyst to reduce back pressure.

It might not sound like much, and it isn’t. But the Senna GTR is also lighter: thanks to a carbon-composite body and carbon-fiber safety cell, it has a dry weight of 1,188 kg (2,619 lbs). That gives it a power-to-weight ratio of 694PS-per-tonne (684hp-per-tonne). Put into context, that’s higher than the power-to-weight ratio of every McLaren car for road or track currently in production — including the road-going Senna.

The engine is mated to the same seven-speed Seamless Shift Gearbox (SSG) dual-clutch automatic that the road-legal Senna has, including a Launch Control function. There are three powertrain models available: Wet, Track, and Race. The Wet setting is new and receives greater support from the ESP and ABS electronic systems. McLaren says it’s intended for use with wet tires.

Obviously, a great deal of attention was given to the aerodynamics of the Senna GTR, resulting in the same levels of downforce as the McLaren Senna but at 15 percent lower speeds. Peak downforce exceeds 1,000 kg (2,205 lbs) — that’s almost the car’s dry weight. On top of all this, the track-exclusive hypercar uses suspension derived from McLaren’s GT3 race program.

As a result of all these upgrades, McLaren says the Senna GTR can lap circuits faster than any of its cars (road or race) outside Formula 1.

The most exclusive member of the British brand’s Ultimate Series will be built in a limited run of 75 cars, all of which are (you’ve guessed it) already sold — despite a starting price of £1.1 million ($1.44 million) plus taxes. First deliveries will begin in September 2019.