About half a year after the coupe version
was unveiled, the Alpina B4 Biturbo open-top model made its debut at the Geneva Motor Show.
The car is technically based on the BMW 435i Convertible, which made its showroom rebut across Germany recently, and features an inline six-cylinder as a power source. Under the hood of the F33 Alpina B4 operates an extensively modified version of the N55 BMW engine which includes, as the name implies, a second turbocharger. The combined result of all modifications is 410 hp and 443 lb-ft of torque, about 30% more than in a series model.
B4 Bi-Turbo Convertible's Exterior Design
The design of the B4 Bi-Turbo Convertible is characterized by short overhangs, precise, long-drawn-shoulder lines, a wide rear and the characteristic metal folding roof. The sporty and purposeful design of the front spoiler is dictated by functional air intakes and operates in conjunction with the modest rear spoiler to improve stability at high speeds. When the roof is open the B4 Bi-Turbo Convertible stands out with its sleek, clean look. The Alpina Classic 20" light alloy wheels fit seamlessly into the overall shape of the Convertible and lend it a particularly elegant presence.
It only takes 20 seconds and the press of a button to close the roof, which is possible up to a speed of 18 km/h, turning the Convertible into a winter- and weather-proof two-door. The shape of the roof line when closed differs from the B4 Bi-Turbo Coupé significantly due to the steeper rake of the rear windscreen, the flat boot lid and subtle rear spoiler - this gives the Convertible a very distinctive and stand-alone appearance.
Interior and Equipment
The new B4 Bi-Turbo model comes with an extensive list of standard equipment, including leather upholstery, electrically adjustable heated sports seats, automatic climate control, xenon headlights, rain sensor and cruise control.
The interior is dominated by refined materials and offers an exclusive ambiance. The door sills, floor mats, emblems in the seatbacks, instrumentation and a hand-stitched sport steering wheel in the finest LAVALINA leather make discreet references to the car's exclusive origins. Virtually no limits are placed on the individual design of a BMW Alpina.