McLaren MSO HS leaked online as ultra-performance version of 675LT

The cat’s out of the bag now. Thanks to US website Jalopnik, the lid has been lifted on McLaren’s top-secret MSO HS hypercar – the ultimate evolution of McLaren’s Super Series range (which until now has been headed by the McLaren 675LT) and what promises to be one of the fastest McLaren road cars ever.

Initially leaked via a handful of Instagram posts, the MSO HS – the HS standing for High Sport, the MSO indicating it’s a product of McLaren Special Operations – is a low-volume special that bridges the gap between the road-going 650S and 675LT and the race-winning 650S GT3 race car.

Its performance stats are impressive. The MSO HS takes the 3.8 litre twin-turbo V8 of the 675LT and massages it to produce 10kW more power, taking it to a new peak of 506kW. Torque output remains the same as the 675LT’s 700Nm.

Though the bodywork is similar, MSO has cleaved roughly 40kg of mass from the 675LT’s frame to give the HS a power-to-weight ratio of 1 kilowatt per 2.55 kilograms. To put that into context, a Ferrari F12 tdf has a power-to-weight of 1kW per 2.64kg.

The liberal use of carbonfibre was a key part of McLaren’s diet plan for the MSO HS, with the lightweight material used to construct the bonnet, side skirts, air intakes and engine cover. The roof is also made of carbon, and features a race-style air scoop to keep the cabin cool – a feature unique to the MSO HS.

Thinner glass helps shed more kilos, as do a set of ultra-lightweight wheels and motorsport-grade carbon ceramic brakes.

Though most of the bodywork is based on the 675LT, the MSO HS replaces the articulated wing/airbrake of the 675LT with a race style carbon fibre wing similar to that used by the McLaren P1 GTR race car. Other additions to the aero package – like a set of carbon-fibre front canards and a deeper front splitter – help the MSO HS generate 220kg of downforce at 240km/h.

The MSO HS also features the same integrated datalogging and camera system that’s offered on the 675LT. With a camera in the front and rear bumpers, plus a forward-facing in-cabin cam, MSO HS owners won’t need to festoon their cars with GoPros at their next track meet.

The car will even use its GPS to record laptimes and provide feedback on where the driver can improve their line.

Only 25 will be built, and all are reportedly accounted for. Why 25? The HS was originally commissioned by just one passionate (and presumably very wealthy) McLaren customer, but the engineering work involved in creating it would have lost McLaren money had the production run been confined to a single example.