Mercedes-Benz is completing the development of an even higher performance version of its SLS AMG ‘Gullwing’ Coupe, which will bear the Black Series Edition moniker.

The hardest and fastest street-legal SLS AMG of them all was recently filmed running some quick laps around the Nürburgring Nordschleife circuit.

Among the key highlights of the Black Series Edition model will be a massaged 6.3-liter V8 producing possibly as much as 650-horses, up from the regular car’s 583hp (591PS) at 6,800rpm and 650Nm (479 lb-ft) at 4,750rpm.

The German sports car will also feature a wider body kit with lightweight carbon fibre panels, a faster transmission, a stiffened suspension and uprated brake and steering systems to improve handling.

We could see Mercedes-Benz unveiling the flagship version of the SLS AMG series as early as this year, though sales would likely follow sometime in 2013.

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