The M2 CS is expected to offer about 445 horsepower, likely from the 3.0-liter twin-turbocharged inline-6 fitted to the M3/M4 instead of the regular M2's single-turbo engine. The regular M2 makes 365 hp while the M2 Competition with the same engine makes 405 hp.
I'm confused by this paragraph. They are saying the M2C makes 405hp with of the N55 single turbo engine? The M2C uses the S55.