This BMW M135i (F21) was purchased with a broken motor. The owner sent the car to BMT Auto’s in Hoogeveen, Netherlands for a better solution. While there the company swapped the factory turbocharged 3.0 L N55 inline-six for a twin-turbo 3.0 L S55 inline-six. The change gifted the car 431 hp and 550 Nm (405 lb-ft) of torque. Behind the motor is a ZF 8HP eight-speed automatic transmission and xDrive AWD drivetrain. The car still retains the factory M135i disc brakes behind 19-inch wheels with Continental SportContact 6 tires. Listen to AutoTopNL review the car in the video below.
Source: BMT Auto’s and AutoTopNL