McLaren 688HS leaked

McLaren has been the victim of a leak after a top-secret, more powerful version of its 675LT appeared on Dutch car blog, AutoGespot.

According to British car magazine Autocar, which also helped leak the images, the car pictured is called the 688HS (HS stands for High Sport) and is an even lighter, faster, hard-core version of the current 675LT Sport Series coupe.

Created by McLaren Special Operations (MSO), in cooperation with a wealthy owner, the new 688HS is said to be one-off special.

Claimed to produce an incredible 506kW (688hp), the 688HS uses the same twin-turbo 3.8-litre V8 as the 675LT but generates an additional 9kW more power and fractionally more torque, compared to the standard car's 497kW/700Nm.

Despite the small power and torque gains, the 688HS is still likely to be quicker than the 2.9 seconds it takes for the 675LT to reach 100km/h because of large weight savings introduced by MSO engineers.

Top speed, meanwhile, isn’t expected  to change from the 675LT’s 325km/h. That’s because of its big aero changes introduced that emphasise downforce over straight line speed.

Biggest changes are the new twin-blade front winglets added on the bumper, a huge new rear spoiler and a modified rear diffuser.

These changes almost certainly hint at the 688HS intended purpose -- a track day tool.

The 688HS is thought to have benefitted from the aero know-how earned from the development of the firm's works-650S GT3 race car that competed -- and won -- this year's Bathurst 12 Hour.

Speaking to Autocar, a spokesman for McLaren said: "This is a bespoke project which will not become a series production model, the details of which are confidential at this stage. Further details will be confirmed further into the project.”

It's not known how much the 688HS would have cost to commission, but the bill is rumoured to be considerably more than $2 million dollars, suddenly making the $620,000 the car-maker charged for the sold-out 675LT Spider sound something of a bargain.