With Mercedes unveiling its E-Class Cabriolet in time for the Geneva Motor Show, tuner of Mercedes-Benz and Mercedes-AMG products Brabus has now turned its attention to another of the three-pointed star’s four-seater convertibles; in this case, the Mercedes-AMG C 63 S Cabriolet.

In Brabus fashion, more is given to where there already was plenty – the C 63 S Cabriolet’s 4.0 litre biturbo V8 goes from its stock 510 hp and 700 Nm output figures to the breathed-upon 650 hp at 5,800 rpm and 820 Nm of torque between 1,750 rpm and 4,500 rpm in 650 Cabrio guise.

The Brabus PowerXtra B40S kit, as the engine upgrade is called in full, encompasses both hardware and software changes for the goal of increased engine output. The twin turbochargers are swapped for units with larger compressors, with each getting a special turbocharger core assembly and reinforced axial bearings.

An auxiliary Brabus PowerXtra module is added to the standard ECU, thus providing its own maps for the electronic boost pressure limiter, injection and ignition. Together with the hardware upgrades, they combine to increase the 4.0 litre biturbo V8’s outputs to the aforementioned levels for a 0-100 km/h time of 3.7 seconds, while top speed is now electronically limited to 320 km/h.

For those who want added sound but without the greater fury, Brabus also offers an all-stainless steel sport exhaust system with electronically controlled flaps, available for sale without the engine tuning. Controllable from within the cabin, the driver can choose between a more subtle sound with the ‘Coming Home’ mode, and a sportier sound with the exhaust flaps open.

To better harness the even more powerful cabriolet’s performance, an optional coilover suspension kit is optionally available for the 650 Cabrio, which works with the standard Ride Control adaptive dampers. Such configured, the suspension offers three damper settings, along with ride height that can be lowered between 20 mm and 40 mm. It can be set independently for the front and rear axles too.

Also available for the Brabus 650 Cabrio are the Brabus Monoblock R Platinum Edition wheels, measuring 9 x 20 inches in front and 10.5 x 20 inches at the rear. The black-painted, forged double spoke wheels are mated to 255/30R20 front and 285/30R20 rear tyres, from either Continental, Pirelli or Yokohama.

Interior upholstery also gets the Brabus touch, where black leather with azure blue elements adorning the 650 Cabrio. Additionally, aluminium pedals and door-lock pins add to the sporting character, as do carbon trim elements along with a Brabus speedometer dial that goes up to 340 km/h.

The Brabus 650 Cabrio is available as either a complete vehicle, or built upon an existing Mercedes-AMG C 63 S Cabriolet in full or in stages.