Alpina BMW B6 Bi-Turbo Coupe
For Alpina, a technology driven company, standstill is a foreign word. Since the introduction of the B7 Bi-Turbo, the engineers from Buchloe, Germany, have been continuously working on the details of the turbo charging and intercooler system.
Consequently, the all-aluminum V8 power plant now produces 540hp (397kW) at a moderate 5500rpm, with a maximum torque of 700Nm from 3000rpm. Two turbo-chargers configured in parallel, each feeding one of the two cylinder banks, with specially developed large diameter exhaust-turbines allow this engine configuration to provide both exceptional power output and an abundance of torque over an especially broad rpm range while maintaining excellent throttle response at low rpm.
The comprehensive high-performance cooling system comprises an indirect inter-cooling system (air-to-water/water-to-air) with short intake tracts and increased inter-cooler flow. The systems excellent thermodynamic efficiency is guaranteed by a large-volume low-temperature inter-cooler radiator, two water-to-air intercoolers placed close to the engine and additional separate motor oil and water coolers.
High-performance MAHLE pistons are designed specifically to deal with temperatures and pressures associated with up to 1.0 bar charging and the engine's 9.2:1 nominal compression ratio. Altogether this results in an impressive specific output of 122.7hp (90kW) per liter and a mean total compression of 20.1 bar. Direct injection and Double-VANOS contribute to the B6 Bi-Turbo's class-leading consumption and emission figures: 10.5 (10.6) l/100km and 244 (247) g/km CO2, Combined cycle, measured according to ECE Norm (data for Convertible in brackets).
Adapted and tested in co-operation with ZF, the advanced SWITCH-TRONIC 8-speed Sport Automatic Transmission sets benchmarks. With Alpina's philosophy the guiding credo, engineers have spent thousands of development and test hours ensuring that no other performance automatic transmission comes close to providing this level of both comfort and performance.
The blend of eight speeds and plenty of torque makes for unparalleled comfortable gear changes with no noticeable interruption to the delivery of power - only the accompanying acoustics and the dynamic rev counter provide feedback as to the workings of the transmission. 700Nm of torque means the B6 Bi-Turbo excels at cruising along at speed in a high gear at minimum rpm, benefiting both consumption and comfort.
Using the Sport (S) Shift Mode a completely different character emerges: the transmission is crisp and unmistakably immediate. The innovative single-cylinder fadeout enables super quick up-shifts which take just milliseconds. Depending on the load on the transmission, the injection of fuel into a given cylinder is interrupted for a fraction of a second, creating the required reduction in torque that the automatic transmission needs for the up-shift. The advantages versus the typical method of timing retardation are noticeably quicker shifts, improved thermo-dynamic efficiency due to reduced exhaust temperatures and lower fuel consumption. Each up-shift is accompanied by a deep back-pressure burble.
The SWITCH-TRONIC buttons, for use in the Manual (M) Shift Mode, are ergonomically and unobtrusively positioned on the back of the steering wheel, and allow the driver to take complete control of the transmission. The system allows for multi-simultaneous downshifts in milliseconds, hereby the transmission will skip several gears depending on engine loads and rpm. In this manner the 8-speed Sport Automatic Transmission with Alpina SWITCH-TRONIC reveals itself as extremely multi-faceted, providing the right shift characteristic for any and all situations.
The Automatic Up-Shift function means that the transmission will up-shift into a higher gear once a certain rpm threshold has been passed in the current gear. In certain driving situations this may not be desired, for example during especially sporty driving or for example when encountering multiple tight hair-pin corners. The simultaneous selection of either Sport, Sport+ or DSC OFF Mode using the Drive Dynamic Control button and the selection of the M Shift Mode (transmission) will deactivate the automatic up-shift function. The transmission will hold the selected gear up to maximum rpm's (electronically limited) and will not automatically up-shift into a higher gear.
The intelligent coupling of state-of-the-art engine and transmission technologies give the B6 Bi-Turbo stunning performance figures: 0-100km/h in 4.4s (4.5s), and a top speed of 320 (317) km/h.
High-performance convertibles and large grand coupés place special demands on their chassis - requiring distinct levels of comfort for easy cruising, safe and neutral handling at high speeds, and light-footed agility for the moments in between. In order to do justice to this broad spectrum of requirements, the new B6 Bi-Turbo features the latest electronic suspension technologies and comes with Drive Performance Control (electronically adjustable dampers) and Dynamic Drive (active roll stabilization) as standard.
This system has been artfully calibrated by Alpina and is tied into other system parameters controlling steering assistance, torque cushioning and the Dynamic Stability Control system. Featuring pronounced Comfort+, Comfort, Sport and Sport+ modes, the B6 Bi-Turbo transitions effortlessly from cultivated luxury convertible to thoroughbred sports car. Across all variables, the Coupé has been set-up to be more sporting and dynamic, and features a rear axle with limited slip differential as standard.
The double tailpipes, with a slightly elliptical shape in typical Alpina style, are designed in titanium and carry small logos that make discreet reference to the origins of the Alpina exhaust system made by Akrapovič. The rear valence, which attractively and elegantly frames the outlet of the tailpipes, additionally integrates the features of a diffuser.
Source: Alpina press