The standard C63 AMG Black Series has 517 hp from its naturally-aspirated 6.3-litre V8 but the guys from GAD thought this wasn’t remotely enough so they replaced this unit with the twin-turbo V8 (M157) unit. The output of this machine is now a scary 850 hp with 1350Nm of torque. Power sent to all 4 wheels thanks to the 4MATIC system and because of the dramatic increase in torque, it features an upgraded MCT gearbox to handle that massive force. 100 km/h comes up in just 3.1 seconds which is 1.1 seconds quicker than standard and will go on to reach 300 km/h from stand still in just 23.5 seconds. One would think with an entire engine replacement that this kit is not cheap and you would be correct. For the entire GAD kit, you will be expected to pay €180 250 and yes this is without the car! WTF???