Texas based tuner Hennessey Performance is offering a preview of their upcoming tuning program that will take the McLaren MP4-12C to a whole new level of performance.
The American company said that it is currently working on adapting the British supercar with their HPE800 Twin Turbo package that will enable the mid-mounted 3.8-litre V8 to deliver no less than 800 horsepower. 
We’re talking about a 200 horses increase over the 600 bhp and 600 Nm of torque produced by the stock version, with this extra ‘juice’ squeezed out by a number of mechanical changes like an upgraded intercooler and air intake system, upgraded turbochargers and a titanium exhaust.
The Hennessey HPE800 McLaren MP4-12C has also received an upgraded fuel and engine management system, an upgraded transmission clutch system, as well as a carbon aero package that gives that car a more aggressive stance.
The Hennessey Performance enhanced MP4-12C sits on monoblock wheels wrapped in Michelin Pilot Super Sport Tires, while its interior features custom upgrades that involve materials such as carbon, Alcantara and leather.

Source: Hennessey Performance