The B3 GT3 limited edition isn’t the only Alpina making its debut at this week’s 2011 Tokyo Motor Show as the boutique automaker also brought along the coupe version of its B6 BiTurbo based on the latest BMW 650i.

Alpina has taken BMW’s 4.4-liter V8 turbo engine to the next level with a series of upgrades including an intercooled dual turbo system and the addition a new titanium exhaust system developed in conjunction with exhaust specialists Akrapovic, that all help to lift output to 540-horsepower at 5,500 rpm and peak torque to 700Nm (516 lb-ft).

A specially modified eight-speed sport automatic transmission from ZF transfers power to the rear wheels. Alpina says that the B6 BiTurbo Coupe goes from 0 to 00km/h in 4.4 seconds and has a top speed of 320 km/h (199 mph).

The B6 BiTurbo rides on a stiffer suspension while the German firm’s engineers have re-calibrated the standard 650i’s electronic aids.

The model displayed in Tokyo is dressed in a matte blue vinyl wrap while Alpina’s subtle exterior makeover also includes a front spoiler with an integrated carbon fiber splitter, a rear diffuser and a rear wing made out of carbon fiber.

There is also a new set of double tailpipes with a slightly elliptical shape on either side of the rear bumper and 20-inch lightweight alloy wheels.

The same subtlety can be found inside with the bespoke instruments, two-tone blue and white leather upholstery and Alpina’s three-spoke sports steering wheel.

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