The output of the 3.0 litre straight-six cylinder engine with high-precision direct injection and Valvetronic has been further increased with the aid of a revised turbocharging system comprising two new ALPINA specific turbochargers and a new high-performance cooling system. The new BMW ALPINA B4 S Bi-Turbo now delivers 324 kW (440 hp) between 5500 rpm and 6250 rpm and a maximum torque of 660 Nm from 3000 rpm to 4500 rpm.
The new engine particularly impresses in the mid-range with an effortless power delivery in addition to an eager willingness to rev to 7000 rpm. Coupled to the excellent ZF 8-Speed Sport-Automatic Transmission it propels the new BMW ALPINA B4 S Bi-Turbo Coupe in just 4.2 seconds (3.9 seconds with all-wheel drive) from 0 to 100 km/h and on to a top speed of 306 km/h (303 km/h with all-wheel drive). BMW Efficient Dynamics technologies such as Auto Start Stop and Sailing contribute to an exemplary fuel consumption of only 7.9 - 8.3 l/100 km and 180 - 190 g/km CO2 combined measured to ECE norm (depending on the model).
To achieve the new BMW ALPINA B4 S Bi-Turbo’s characteristic, torque driven and spontaneous power delivery without sacrificing fuel efficiency necessitates state-of-the-art engine technology in a clever package. The application of Bi-Turbo charging provides excellent throttle response and pick-up due to the low mass inertia of smaller turbocharger running gear while generating sufficient throughput for top-end performance. The design and construction of the excellent BMW 3.0 litre straight-six cylinder (N55) engine serves as a starting-point for a specially cast aluminium crankcase with reinforced bed plate and Bi-Turbo capable flanges. The latter facilitate the mounting of two turbochargers along with their oil and water feeds and a close-coupled catalytic converter arrangement.
This latest iteration of the 3.0 litre straight-six cylinder engine receives new ALPINA specific turbochargers for even more output and a new piston crown cooling system. ALPINA air intake ducts guide the air with minimal losses from the air intake via the air filter housing to the turbochargers. A high-capacity intercooler with optimised collector boxes made from aluminium allows the full exploitation of the engine’s output potential. The high-performance cooling system has been further adapted concordant to the latest increase in engine output – the external water cooler and external oil cooler have grown in capacity by more than 15 % and 35 % respectively.