As its $315,000 Business Lounge V-class and “ultimate city sports car” have displayed, Brabus is not a company that is capable of small-scale thinking. It’s go big or get the hell out of Bottrop. The most recent example is the Brabus Rocket 900 Cabrio, an open-top version of the firm’s extreme S65 AMG coupe that we saw early last year. Altering one of the most powerful production vehicles on the planet might seem outrageous, but that’s exactly the point: to step over the line of a reasonable purpose.
The masterminds at AMG already have a beast in their stable with the S65 convertible. Their twin-turbo V-12 powerplants churn out a claimed 621 horsepower and 738 lb-ft of torque. But Brabus makes that output look like peanuts. After extensive component upgrades and tuning, the Rocket 900 Cabrio claims 888 horsepower and 1106 lb-ft of torque at 4200 rpm, although it’s electronically limited to 885 lb-ft.
Brabus started the aftermarket customization process by enlarging the V-12’s displacement from 366 to 384 cubic inches, or from 6.0 liters to 6.3 liters. A billet-steel crankshaft provides a longer stroke, while billet-steel connecting rods push special forged pistons into cylinders that have been bored out. Beefier turbochargers provide more boost, and specialized exhaust manifolds, a high-performance exhaust, larger downpipes, and free-flow catalysts enhance the breathing. The intake has also been revised with a Brabus-dev...