German tuner 9ff is claiming a new top-speed world record for road-registered cars of a blistering 241.1mph. The record, set by 9ff boss Jan Fatthauer in the company’s new 9F-V400, was achieved at the Nardo test track in Italy. It cracks the previous record of 240.1mph set by Andy Wallace driving a McLaren F1 in 1998. Based on the 911 GT2, the 9F-V400 runs a heavily tuned twin-turbo 3.8 flat six-cylinder engine that’s claimed to pump out 828bhp at 7200rpm and 649lb ft of torque at 6450rpm. Among its highlights are forged titanium connecting rods, forged aluminium pistons, reworked KKK turbochargers, water-cooled intercoolers, an electrically regulated oil cooling system and a revised Bosch Motronic ME7.8 electronics package. It is backed by a reinforced six-speed gearbox running unique ratios and working through a new three-plate clutch, a heavily revised aerodynamic package and a series of weight-saving measures; these include a carbonfibre roof, bonnet, engine lid, doors and mirrors. They bring the car’s weight down to a claimed 1300kg and provide it with a power-to-weight ratio of 637bhp per tonne. 9ff says it plans to produce up to 20 examples of the 9F-V400. Production of the first three cars is already at an advanced stage, according to Fatthauer, with the fourth – a right-hand-drive example destined for Japan – set to get underway next week. The price? A cool £278,000.