[V8FunNaturally]

Swamp could you reverse the plotting order of your curves (plotting the highest gear first, lowest gear last), this would better show the optimal shifting points occuring much below redline for the boosted M4 engine.

Also typo correction, in your original post 2nd to last paragraph you typed M4, instead of M3 (E92) in "whereas the M4 tapers off much less dramatically".

These curves show in a mathematical way what could be expected that a turbo engine is going to be much less pleasurable to drive than naturally aspirated. Simply because turbos cannot spool fast enough to keep a low compression ratio engine (off boost) breathing at high RPM AND have zero lag at low RPM. This will not be a driver's car (as far as the engine is concerned for starters) the way the E92 and E46 are.

Yes, it is going to be silly/idiotic kind of fun in the low to midrange RPM because of the available torque, but not the mature linear high reving fun that is much more exhilarating from a naturally aspirated engine.

Now I understand why all the M4 used for the taxi ride BMW pre-views with BMW DTM drivers were all manuals. Any efficiently designed DCT will not use the upper RPM range above the optimal crossing. So it should sound even more dull than the manuals.

The only way to improve this situation with a DCT is to have as many gears as possible, that means not 7 but 10 or more. Obviously this isn't possible and desirable. So that's it, this engine is essentially wothless above those RPMs. Even for mileage. The only benefit for going to redline will be sound and we already know it is not going to be the forte for that engine.