A track-only version of the McLaren 650S coupé, called the 650S Sprint, has made its debut at the Pebble Beach Concours in the US.
It benefits from a host of revisions that McLaren states allows the car to "deliver a more engaging GT racing experience, without losing any of the refinement and balance found in the road car".
Among the changes are recalibrated engine and transmission control systems, which are reputed to offer a more responsive and involving nature.
The Sprint otherwise retains the 650S' twin-turbocharged 3.8-litre V8, which produces 641bhp and 500lb ft, and power is sent to the rear wheels by the same seven-speed dual-clutch automatic transmission. In standard form this helps the 650S sprint from 0-60mph in 3.0sec.
Other developments include an revised Brake Steer system – which can brake the inside rear wheel for better cornering – and a new race configuration for McLaren's ProActive Chassis Control system.
Further upgrades include retuned active aerodynamics, a lowered ride height, recalibrated adaptive dampers, 19-inch centre-locking wheels shod with Pirelli slick or wet tyres, an onboard air jacking system and improved brakes.
Inside, the McLaren's stripped-out cabin features an FIA-approved rollcage, integrated fire extinguisher and a new lightweight carbonfibre racing seat with six-point harness. Though luxuries inside are few, air conditioning has been retained.
McLaren says the 650S Sprint also shares features with the 650S GT3 racer, which made its debut at the Goodwood Festival of Speed this summer, including the GT3's larger motorsport-derived fuel tank, upgraded radiator and new front wing louvres.