I just checked around and found this:

" There is nothing to replace displacement other than more displacement. This philosophy is also true for the new Mercedes SL 600 and that's why the BRABUS engineers developed the BRABUS S V12 Biturbo increased-displacement engine. The BRABUS engine sets new performance standards with a maximum power output of 640 hp / 471 kW and a maximum torque of 1,026 Nm from just 1,750 rpm "