Mercedes SL-Class with a Compound-Turbo OM648

Black Smoke Racing debuted a new project at the 2026 American Car Show in Finland. The company started with a Mercedes SL-Class (R230) and dramatically change the appearance with an AMG GT-R body kit. In the engine bay they swapped a compound-turbocharged 3.2 L OM648 inline-six. Garrett reports the compound-turbo system uses a G40-900 turbocharger and G47-1850 turbocharger. Black Smoke Racing cooled the charged air with a custom water-to-air intercooler with two cores and a custom air-to-air intercooler with three cores. They estimate this is enough cooling capacity for 7 bar (101 psi) of boost or 2500 hp (1838 kW). Behind the monster motor is a G-force dogbox and Winters quick-change rear end. Black Smoke Racing will be releasing more details on the project soon.

Source: Black Smoke Racing FB page and Garrett FB page