All indications are that BMW won't, in the end, be producing an M7 based on its new-generation F01 7 Series. That would've been cool, but before the Mercedes S63 AMG and Audi S8 can breathe a sigh of relief, Bavaria's pseudo-factory partner Alpina has something to say about it, and this is what it spake: the B7 Bi-Turbo - a BMW 7 Series with an attitude. At its heart is a twin-turbo 4.4-liter V8, which produces 507 horsepower thanks to larger-vane turbos and a new intercooler, driving through a retuned Switch-Tronic ZF six-speed automatic transmission, and a recalibrated suspension designed to optimize the balance between supercar control and luxury sedan comfort. 4.7 seconds is all it takes to hustle to 60 mph, while custom 21-inch rims riding on conventional rubber replace the stock run-flats and a bespoke leather and wood interior round out the package. You can read more about in the press release after the jump and view all its angles in the gallery below.