It’s been a year and half since we shared this 2002 Mercedes C230K project from Florida. Since then they finished replacing the factory supercharged 2.3 L M111 inline-four and 5G-Tronic (722.6) five-speed automatic transmission for a turbocharged 2.8 L (M104.900) VR6 and 716.648 six-speed manual transmission. To get the engine to work, they converted a MK3 VR6 oil pan to a rear sump and modified the stock pistons to lower the compression and gain extra valve clearance. The engine also features a 75 mm throttle body, Holset HX35 turbocharger, and methanol injection. They were able to mate the VR6 to the manual transmission thanks to a custom adapter plate and modified VR6 24v flywheel. However after breaking those at the drag strip, they replaced the manual with a 722.351 automatic from a 1990 W126 sedan. They send the power to the rear wheels through a welded 185 mm differential with 3.27 gears. You can view more photos and details in the project’s build thread.
Source: VWVortex (build thread) and Junkyarddawg Fixit via Piotr