Originally Posted by ace996
That is the theory most believeable at this point. The flap would then, at best, help with cruising MPG...not something I'm really interested in addressing, though.
Now, if there was a hood scoop instead of a vent, then we would in effect be installing a stronger pump where a weak one exists (or where one does not exist) and would increase airbox pressure and thus VE.
The only issue with that is...aesthetics. I'm no designer, but I've a bitch of a time trying to figure out a way to elegantly add a scoop. I think the most acceptable addition would be a NACA duct, aiming in. And for symetery's sake, a reverse NACA could be added to the other (faux) side as a draw-out/vent of engine heat/air.
Will I do that?...the magic 8ball says no. But I think that would work.
I think we've now discussed this to death. The only thing left is for someone to produce some actual figures of the air intake in "real world" driving conditions. I'm afraid I can't do that due to lack of access to one of your M3s. Out of interest what do they cost in the USA and what is the present price of your fuel?