Figures released by specialist Porsche tuner 9ff detail a great deal of improvement in the Carrera GT's power output as well as straight-line performance.

9ff is a specialist Porsche tuner, so if anyone knows how to work a Porsche engine it is these guys. The Porsche Carrera GT is one of the most accomplished, if severely undermarketed road cars built in the past few years. That 5.7-litre V10 produces 612hp/ 456kW and 590Nm of torque, both of which can whirl the car from standstill to 100km/h in 3.9 seconds topping off at a limited 334km/h (207mph).

The tuner 9ff thought this might not be enough. Luckily they had got themselves one of the 1,270 units of the Carrera GT sold and modified it to 900hp/ 671kW. A carbon fibre rear wing was fitted, an electronic suspension system that lowers the car, 19-inch magnesium wheels and a ceramic dual-disk clutch were all added.

Performance improvements are evident in that the car's 0 - 100km/h spring time now sits at 3.2 seconds with top speed upped to 390 km/h (242 mph).

You can get this car from 9ff for 452,000 Euros or 635,000 USD.

9ff GTT 900 details released - based on Carrera GT