Originally Posted by CSanto
I say Needs to be 450 Minimum. That CLA45 will make 400hp easily with some work. An M3 should be able to make 500 with a tune/minor mods.
If the n54/n55 is any indicator of tunability of the s55, I would think the
M3/M4 could make nearly 500 with mechanical bolt ons(DP's, exhaust, intake, IC). FBO and tune.. High 500's low 600's