Originally Posted by mapezzul
I know what they put into their cars (I've spent some time with Andy) and also know that they have had some time to work on things since that original N55 project- they can rework a lot of things and let's not forget that BMW M GmbH has been assisting them a great deal over the last few years...
I would't be surprised if there is a modified bedplate and two turbos to go along with other typical Alpina tuning. But maybe they will stick with the N54 although they will have a hard time getting one that isn't from a crate. I really don't follow their prototyping as close as I should... as I love the cars a great deal and up until the M550d I swore that Alpina was the only way to get a true High performance diesel..
What's your take on what is under that hood?
I think the N55 would have to be modified too much (just as you said as well) in order for them to be a good platform and to be more powerful than the current B3 S - and let's not forget they need some room for an "S" variant later on.
I agree with you that they'll probably work closely together with the M GmbH, and I think it will be a straight six biturbo engine - probably somewhat similar to what they did with the M5/B5 combo, i.e. a more sophisticated version for the M3 and a slightly simpler version for the Alpina.
The only problem I currently have with that speculation is that Alpina nowadays always uses a BMW engine and modifies it - and currently there's only the N54 that is suitable but which is slowly being phased out of BMW's engine offer. Except if they're working on an update for that engine in order to place it above the N55 in some specific sports-oriented models, which would make sense as well; and then use that as a basis for the new M3.
We'll see but I'm quite curious how Alpina will solve the dilemma of having to bring out a model that has to be stronger than the current E9x but less powerful than the new M3 that will have 450hp with a very similar engine setup.