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-aluminium 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 litre 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).
TRANSMISSION – Eight-Speed All-Rounder
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 (known as ‘Einzelzylinderausblendung’ in German) 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 unobstrusively 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 down-shifts 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 funtion. 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.
EXHAUST SYSTEM – Pure-bred, Sonorous, Lightweight
For the first time, Alpina has collaborated with Akrapovi? on the development of a lightweight exhaust system made from high-strength titanium. Faithful to the guiding principle of ‘form follows function’, the entire system is noted not only for its acoustics and appearance, but also for its technical refinements. In addition to a weight-saving of 45% compared to the conventional use of stainless steel, the exhaust system also boasts impressive technical details. The engineers from Alpina and Akrapovi? have achieved quite a feat, managing to retain a diameter of 2 x 70mm throughout the entire length of the exhaust system, despite the tricky ‘packaging’. In conjunction with further design refinements, exhaust back-pressure is reduced to an absolute minimum.
In interaction with the powerful engine, the exhaust system generates a backdrop of deep, sonorous eight-cylinder sound – powerful, sporty, but never obtrusive, due to intelligent, controllable exhaust valves. These offer the driver a special degree of influence over the sound experience, and can be controlled using the Drive Performance Control. In Comfort+ and Comfort Mode the valves are closed, opening at 3000rpm, regardless of the selected gear. In 1st and 2nd gear decisive use of the accelerator will cause the valves to open (at approx. 60% load) and the B6 Bi-Turbo to elicit a special symphony from the tailpipes during dynamic bursts of acceleration. As befits the character of the B6 Bi-Turbo in Sport and Sport+ Modes, the exhaust valves remain open at all times.
CHASSIS – Dynamic Comfort
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 stabilisation) 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 thorough-bred 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.
Specific springs, increased front wheel camber and a subtle adjustment of the toe-in in conjunction with a 20″ wheel-tyre combination all serve to produce a very agile chassis set-up. The lightweight 20″ Alpina CLASSIC wheels, with MICHELIN PILOT SUPER SPORT tyres in the dimensions 255/35 ZR20 front and 285/30 ZR20 rear, contribute significantly to the direct handling and precise steering. Conventional tyres are used to promote ride comfort.
EXTERIOR DESIGN – Exciting Details, Functional Aerodynamics
The BMW 6-Series is marked by an elegant and dynamic design as well as excellent aerodynamic properties. Alpina gives the new B6 Bi-Turbo a unique, powerful appearance which elegantly underlines the sporty character of this beautiful coupé and convertible.
The exterior components that influence the aerodynamic properties of the B6 Bi-Turbo are not just there for aesthetic reasons – their design is subject primarily to functional premises and plays a central role in achieving excellent high speed stability. Take for example the front spoiler with the integrated carbon fibre front splitter. It causes more air to flow over and around the vehicle, simultaneously reducing the air masses which flow underneath by more than 10%. This leads to a noticeable stabilisation of the front-end at high speeds and plays a role in reducing any tendencies to understeer. The front spoiler, in conjunction with the rear spoiler, ensures that the B6 Bi-Turbo is very well ‘tethered’ overall. Uplift on the front axle is reduced by 14% and tends towards a value of zero on the rear axle from a speed of 150km/h. Instead of the rear spoiler, the Coupé is also available with a rear wing – which despite an impressive visual impact, fits precisely the contours of the rear area and reduces drag.
All these components also ensure the effective flow of air to various cooler groups, such as the inter-coolers and engine cooling system. One special detail: the high-performance brakes, with a diameter of 374mm front and 345mm rear, are additionally supplied with cooling air by a specially constructed NACA air intake on the front underbody.
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 Akrapovi?. The rear valence, which attractively and elegantly frames the outlet of the tailpipes, additionally integrates the features of a diffuser.
INTERIOR & EQUIPMENT – Master Craftsmanship, Exclusive Personalisation
Blue Alpina instruments with high resolution information display with black panel LCD technology. A sport steering wheel, hand-stitched in LAVALINA leather. Blue illuminated entry sills with logo. Or the classic Alpina exotic wood equipment in myrtle – an exclusive burl wood of the laurel family, which grows only on the Pacific coast of the USA. These are just some of the elegant features of the interior that point to the exclusive origins of the B6 Bi-Turbo – just for connoisseurs.
Naturally, no limits are set on the personal predilections of customers. From the paintwork to the interior trims to the colour of the upholstery – everything offered by the extensive BMW and Alpina equipment range is available. Seldom does a BMW Alpina leave Buchloe without making use of the virtually limitless personalisation options offered by the Alpina Manufaktur. Our philosophy dictates that the customer can design his or her own individual interior – made by skilled craftsmen in our leather workshop.
The B6 Bi-Turbo features an extensive range of standard equipment, including leather upholstery, fully adjustable comfort seats with heating system, navigation system with preparation for Bluetooth mobile phone, USB audio interface, Xenon lights and LED fog lights.
Pictures, Images, Photos, Pics, taken from BMW Press Release.