Originally Posted by Uli_HH
clear is that an 3.0ltr. I6 with BiTurbo layout based on the N55 couldnīt reach the wished HP-Numbers from 450+ without reliability issues ...
I continue to disagree with this notion.
First off, 150hp/L is not at all out of reach. There have been ~300hp 2L turbo motors out there in production cars for over a decade, probably more. So 450hp is achievable from 3L.
Secondly, there could be some mild-hybrid assistance. Maybe not Kers, but soemthing else like an electric motor built into the engine behind the flywheel as seen on some mild hybrids. This could add as much as 50hp, maybe more.
Third, they may have found a way to use the larger bore (note *not stroke*, the S54 and N55 have the same stroke, and I still remain firm in my belief that a stroker is out of the question) as seen on the S54 but with an aluminum block instead. This would allow 3.2L and at 150hp/L, this would yield 480hp. They could even combine this with the solution above for over 500hp.