Originally Posted by CanAutM3
Agreed on the fact that in the past, M engines are based on "vanilla" engines. But historically they have always been extensively modified, with not much left in common with their vanilla counterpart. Hopefully BMW M will be doing the same thing here and not a carry over like they did in the 1M. IMO, an ///M engine should have the soul of Motorsport, that is what ///M stands for.
I think that we can absolutely bet on that.
Just the fact that power output will got from ~300hp-~320hp to roughly ~450hp suggests there is going to be some major modifications. In fact we already know that the engine will use at least two turbochargers vs. the single dual-scroll turbocharger employed by the N55.
There may yet be a displacement increase to 3.2L also, though that remains complete speculation.
We do know (or are virtually certain) that one M staple of the past - individual throttle bodies per cylinder will not be making a return. Like the new S63Tu, we can expect Valvetronic thorttle control instead.
I also think we will see some innovative induction system employed to reduce turbo lag. Perhaps, just for example, we could see tri-scoll turbochargers being fed from 3 cylinders each. The much rumored electric turbo system may also make an appearance. There are other possibilities such as variable geometry which also eliminates the wastegate.
Still plenty of time to speculate yet.