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German tuner Brabus upgrades Mercedes-Benz's new 4.6-liter and 5.5-liter twin-turbo V8 engines to deliver up to 512 hp and 610 hp, respectively. Brabus' plug-and-play ECU map for the CL550 gets you a claimed 483 hp right quick. On the CL63 and S63 AMG, Brabus has a chip good for 610 hp and 737 lb-ft of torque. Expect many more tuners to start looking for more power from the Mercedes biturbo V8s.
Source: Insideline.