I just wanted to resurrect this thread of mine, because I'm now reading that there are more whispers of the twin turbo V8 from BMW.
Apparently it will also be in the new 2009 BMW X6 SUV coming in late 2008.
These reports do in fact state it will be the 4.8 liter V8, not a smaller V8 like I had thought.
And rumor is now it's rated at 410 hp.
Again, I will BET that if in fact it is rated at 410 hp is is underrated by at least 15 hp.
The current 4.8 liter V8 is rated at 360 hp, but for twin turbocharged duty the compression ratio would surely need to be dropped which would drop the NA version to around 340-350 without the turbos.
But add a measly 6-7 psi of boost to each turbo and I'd have to think it would add more than 50-60 hp to the car.
But again, either way, how sweet would that engine be in a 5 series.
Rated at 410 hp and probably equal or more likely slightly more torque (but probably really pushing 425+ hp and 450+ lbs-ft of torque out would just be great.
Call it the 555i (nicknamed the Tri-5i)
With a PROcede you'd be well past V-10 M5 power. D@mn!