Originally Posted by T Bone
More likely a packaging issue.....see how tight the S65 / S85 engines are?? No room.
If Audi found room on a very similar engine layout (V8, 4 valve/cylinder, quad OHC) there is no reason BMW couldn't have. See image below - you can see the DI components. DI also fits in perfectly with BMWs efficient dynamics paradigm. Maybe BMWs technology can reach requirements for 7,000 rpm (335i) but not 8400. Or maybe they wanted a system good for 8600-8700 rpm. Maybe Audi is simply ahead of BMW here. If you say who got a V8, DI, 8000+ rpm car to market first, Audi is way ahead of BMW since they had this back in 2006 in the RS4 (mules likely fully functional in 2004). It is now 2008.
As I have said repeatedly no excuses for BWM on this one.