M3 convertible transformed into open-top monster by fitting the twin-turbo V8 from the X6 M.
Manhart Racing has quickly followed up its M5 program with something special for the BMW M3 Convertible, increasing the cabrio's output to a lethal 655 horsepower. Software upgrades and a new Akrapovic Evolution Titanium exhaust system were added to a 4.4-liter twin-turbo V8 borrowed from an X6 M, which then replaced the M3's 4.0-liter V8 unit. The result was a significant boost in power, which is now rated at 655 hp and 719 pound-feet of torque, and a new stop speed of 198 mph.
That additional 235 horses is handled with the addition of an MHR braking system and a 20-inch MHR Concave One Ultralight forged alloys. Modest exterior mods include a carbon-fiber hood with GTR air intakes, mirror caps and diffuser.