BMW Z4 sDrive35is by Kelleners Sport

German tuner Kelleners Sport has turned the BMW Z4 sDrive35is into a real rager. The power upgrade involves a tuning of the 3.0 liter twin-turbocharged inline six-cylinder unit up to an output of 405 PS (298 kW / 400 bhp) and 539 Nm (398 lb-ft) of torque. That's quite a gain over the already impressive series output of 340 PS (250kW/ 335 bhp) and 450Nm (332 lb-ft) of torque - 500Nm (369 lb-ft