It consequently features a twin-turbocharged 3.0-litre straight-six petrol engine that produces 404bhp and 443lb ft.
The manufacturer claims that the B4 will sprint from 0-62mph in just 4.2sec and go on to a top speed of 190mph.
Besides the standard BMW 4-series accoutrements, it also benefits from myriad upgrades, including Alpina's trademark front and rear spoilers - additions that are reputed to increase the car's high-speed stability.
Adaptive damping is standard, as are non run-flat Michelin Pilot Super Sport tyres, which Alpina says improve the ride comfort and grip levels. Other changes include a modified exhaust system.
The new Alpina B4 Bi-Turbo is expected to arrive in the UK in mid-2014. Prices are rumoured to start at around the £60k mark.
In 2013 Alpina enjoyed a record year, selling 1400 cars globally and 300 in Japan. The company, which sold its first car in Japan in 1979, usually only sells 200 in the country each year.
Despite Japanese buyers generally preferring petrol models, Alpina says that the popularity of diesel is beginning to grow. This is partly due to improvements in efficiency and cleanliness, but also due to the increasing cost of petrol.
BMW has also been strongly pushing 'clean diesel' in Japan recently, helping swing customer opinions.
Alpina has also recently launched a new D3 Bi-Turbo saloon and estate.
Jim Holder / Hilton Holloway