Originally Posted by Diver
My current guess on the engine for the M3/M4 is 3.0 L, 2 bar of boost, larger twin scroll turbo plus electric supercharger. The new intake setup will be much like the N55 with cylinder shutdown similar to that used by some domestic V8 engines. The price differential between coupe and sedan will be greater than before. No matter what happens, this will be the ultimate in personal transportation.
With slightly larger twin power turbos and more free flowing heads compared to the old regular mini turbos with restrictive heads used on the n54, the f80 won't need any more than 1 bar boost (14.5psi) to get 450hp. Maybe you meant 2 bar as in total pressure, 1bar atmosphere and 1bar boost.