The new Ultimate Luxury Driving Machine arrives

Woodcliff Lake, New Jersey, November 8, 2002…It has been barely a year since BMW’s “New 7” was introduced, but what an eventful year for BMW. No mere evolutionary product, The New 7 was instead a bold statement about who BMW is, what BMW stands for, and where BMW intends to go. “With help from its suppliers,” stated no less august a source than Automotive Engineering International in its March ‘02 issue, “BMW has produced a vehicle that blazes the engineering trail with innovations that will influence passenger vehicles for years to come. The new BMW 7 Series was selected by the readers and editors of AEI as Best Engineered Vehicle for 2002 because it points the way not only for luxury/performance sedans but also for other vehicle segments.”

Heart of the 760Li: a new V-12 engine of dazzling technology and performance:
As BMW had offered a 12-cylinder model in the previous 7 Series, the 750iL, it was natural and expected that a 12-cylinder version of the new Series would in time make its debut.

The 750iL, offered through 2001, was powered by a V-12 of 5.4 liters with single overhead camshafts and 2 valves per cylinder; that engine’s output was 326 horsepower – a figure now matched by the 7 Series’ V-8. The V-12 powering the new 760Li is completely new, with 6.0 liters of displacement, dual overhead camshafts (per cylinder bank) and 4 valves per cylinder. Designated N73, it is also related to the N62 V-8 engine that powers the two 745 models, in that the two engines share key technologies and overall engineering architecture; yet it also introduces groundbreaking new technologies of its own.

The V-12 configuration has long been recognized as an ultimate power plant concept, suited for top-class vehicles. Its physics are ideal: 12 cylinders arranged in a 60˚ “vee” of two cylinder banks are perfectly balanced; combined with the relatively even power pulses of so many cylinders, this results in a supremely smooth propulsion unit.

This V-12 is also a supremely powerful unit, delivering a monumental 438 horsepower and 444 lb-ft. of torque; for perspective, compare this to the 325 hp and 330 lb-ft. that give the 745i its 0-60-mph capability of 5.9 seconds and you can easily envision the performance potential of the V-12!

Let’s take a look now at the most significant new technology in this new engine: direct fuel injection. Indeed, this is the first direct-injected gasoline V-12 engine ever offered in a production automobile, and the first direct-injected gasoline engine to meet contemporary expectations regarding emission control.

Direct fuel injection means injection of the fuel directly into the combustion chamber, rather into the intake port as is the norm; it has been chosen and developed by BMW’s power train engineers to boost power output and fuel efficiency to higher levels than could be achieved with conventional fuel injection. BMW’s system operates on a stoichiometrically optimum fuel-air mixture and can be emission-controlled by conventional, proven 3-way catalyst technology. By contrast, other direct-injection concepts currently under development in the auto industry (such as lean-burn or stratified-charge) can achieve greater fuel-efficiency gains than the concept chosen by BMW, but these depend on unproven “deNOx” catalyst technology and require sulfur-free fuel, which is not universally available. Thus BMW has deployed a technology that is actually usable in the real world at present.

A close look at BMW’s direct fuel injection:
The injector nozzles are positioned within the combustion chambers, near the intake valves. The combustion chambers themselves are configured – and fully machined – for minimum emissions and noise and maximum performance. Fuel is supplied to the nozzles via a “common rail” (a technology partly responsible for the excellent performance of diesel engines offered today in Europe ) in which fuel pressure is maintained at high levels between 30 and 100 bar (435-3,000 lb./sq in.); the higher the injection pressure, the finer the fuel droplets and the better the combustion process. This pressure is generated by one mechanical pump for each cylinder bank, positioned above the exhaust camshaft, and driven by a dedicated cam.

This high pressure – far higher than that supplied by the electric fuel pump of conventionally fuel-injected engines – is necessitated by the fact that fuel is being injected directly into the cylinders, where high combustion pressures prevail. As in other contemporary engines, the timing and quantity of fuel injected are controlled via electromagnetic valves by the engine’s electronic management system.

An extra-high compression ratio, 11.3:1 vs. the V-8’s 10.5:1, also contributes to the engine’s high performance and the excellent fuel efficiency relative to its capabilities.

Continuing the innovations pioneered in the 7 Series V-8:
In addition to its own exclusive direct fuel injection, the new V-12 shares most of the advanced technologies that made their debut with the new N62 V-8 in the 7 Series a year ago. Among these innovations:
Valvetronic: revolutionary new “breathing” concept. As a BMW-patented world first, Valvetronic dispenses with a conventional throttle and, instead, varies valve lift to regulate engine power.

The Valvetronic mechanism sits atop the intake valves on both cylinder banks. Each of the engine’s 48 valves (4 per cylinder) is actuated as the camshaft lobe deflects a finger-type rocker arm. On the intake side, however, there is an additional element between the cam lobe and rocker arm, called an intermediate follower.

Upon contact by the camshaft lobe, the intermediate follower actuates the rocker arm and, in turn, the valve. The intermediate follower is positioned by an eccentric shaft that can be rotated by a servo motor; this shaft, whose commands come from the electronic engine management system in response to the driver’s accelerator-pedal movements, varies the intermediate follower’s pivot point, which determines the amount of valve lift. Lift can be varied between 0.2 mm and 9.8 mm, providing a range of engine operation all the way from idling to full power. Valvetronic provides abundant advantages:

• Greater efficiency. By eliminating the “pumping losses” associated with a throttle, Valvetronic significantly improves efficiency in low-load operation, i.e. in gentle to moderate driving. As most driving is done in this range, a significant improvement in overall fuel efficiency results.
• More spontaneous engine response. Elimination of the throttle brings atmospheric pressure right up to the cylinder, improving engine response to the accelerator.
• More power. Valvetronic allows higher valve lift than would be feasible with a conventional valve system, thereby increasing the engine’s maximum power output.

Double VANOS variable valve timing. In addition to Valvetronic’s variation of valve lift, BMW’s Double VANOS system varies valve timing by rotating the intake and exhaust camshafts steplessly between “earliest” and “latest” settings for further optimization of engine power, emissions and fuel efficiency. VANOS stands for VAriable NOckenwellen Steuerung, German for “variable camshaft control.” This is not a particular feature of the N62 or N73, as it is present in other current BMW engines; but the combination of VANOS and Valvetronic is exclusive to the new “N” family of power plants.

Liquid-cooled alternator. Continuing an advanced feature of BMW’s top luxury-model engines, the 760Li’s alternator is liquid-cooled. It is more compact than conventional air-cooled alternators, produces more electrical power, and is fully encapsulated for exceptional quietness. Aluminum construction. For lightweight and longwearing durability, the engine’s cylinder block is of Alusil, or silicon-impregnated cast aluminum. After casting, a “soft honing” machine removes just enough of the aluminum from the cylinder walls to leave silicon crystals as their ultra-hard working. The engine’s weight of 280 kg, or 617 lb., is quite moderate considering its size and power.

Automatic Hold: “hill holder” or no-creep function:
Via the iDrive monitor’s Configuration menu, the driver can select the Automatic Hold feature. This automatically holds hydraulic pressure to the four wheel brakes anytime the vehicle comes to a stop, eliminating any tendency of the vehicle to “creep” when the engine is idling and the transmission engaged. The feature can also hold the vehicle stationary when it is stopped on a hill; also, when it is activated the electromechanical parking brake engages automatically anytime the engine is switched off. “Auto P” appears in the instrument cluster when Auto Hold is selected.

Handling, ride and braking: all the advances of The New 7, plus additional standard features:
Fully as advanced as the new 7 Series’ power train, driver interface and design are its chassis features. It was no coincidence that European Car discovered “that we were driving the new 7 Series as if it were a 3 Series,” nor that Germany’s authoritative auto motor und sport discovered “astoundingly agile handling” (October 2, ’01). This after the German magazine raved about the 7’s “first-class riding comfort,” specifically its ability to soak up short as well as long undulations in the road surface.

The 7’s remarkable road capabilities stem from a constellation of high-caliber chassis engineering, including:

• An immensely strong, rigid body/chassis unit, achieved by greater use of high-strength steels, new-age adhesives and all-around engineering for strength and vibration resistance without excess weight. Aluminum hood and front fenders help optimize the unit’s strength-to-weight ratio and the vehicle’s weight distribution.
• Aluminum suspension components, which reduce “unsprung weight” – that mass that must move up and down with the wheels as they encounter road irregularities. This markedly improves riding comfort and, on any rough road surface, handling as well.
• Active Roll Stabilization. An electrohydraulic system that controls active anti-roll (stabilizer) bars in response to cornering forces to reduce body roll or “lean.” 7 Series vehicles corner amazingly “flat” – so much so that this just has to be experienced to be believed.
• Variable-ratio, variable-assist rack-and-pinion power steering. The Servotronic vehicle-speed-sensitive power assist combines with a variable ratio to produce unmatched steering response, precision, and road feel.

On the 745 models, an additional feature – Electronic Damping Control – is available to make their combination of riding comfort and handling prowess even more amazing. On those models, EDC comes in an optional Adaptive Ride Package that also includes self-leveling rear air springs; on the 760Li, both these features are standard.

EDC was also standard on the previous V-12 model, but the new version is markedly evolved. Whereas the previous EDC automatically switched the shock absorbers among three levels of firmness according to road and driving conditions, the new system is stepless, adjusting them to any level of firmness between their softest and firmest settings:

• Ride firmness is always at the optimum level for current road conditions, speed, and the load the vehicle is carrying (passengers and luggage).
• On smooth roads, the shock absorbers are kept “soft” for best riding comfort.
• When the vehicle is rounding a sharp corner or curve, they are instantly adjusted to a firmer, just-right level.
• When the vehicle encounters irregular road surfaces, such as bumps or ripples (“washboard” surface), the shocks are automatically adjusted to the optimum level of firmness to control ride motions, keep riding comfort at an acceptable level, and maintain adhesion to the road.
• Additionally, a Sport setting selected via a console switch increases firmness for a sportier driving feel. In another refinement over the previous system, the Sport mode now varies the shock absorber according to conditions, but always keeps them at a higher level of firmness than in the Comfort setting. Steering assist is also reduced in this setting.

Rear air suspension: a new path to self-leveling:
The 760Li’s standard self-leveling rear suspension represents another advance over the predecessor models.

In the new system, air springs replace the rear coil springs; self-leveling is via an electric air compressor and sensors that recognize changes in vehicle loading. When the sensors detect a longer-term change in the ride height at the rear (as with a full passenger load or heavy loads in the trunk), the pressure in the air springs is increased to bring the vehicle back to its normal attitude. The 7 Series’ standard Bi-xenon headlights also incorporate dynamic auto-leveling – their aim is instantly adjusted to transitory changes in vehicle attitude, such as acceleration and braking, so with regard to self-leveling, the 760Li truly has all its bases covered.

Brakes: among BMW’s largest, most powerful ever:
All 7 Series models have ventilated discs all around, generously sized at 348 mm/13.6 in. at the front and 345 mm/13.7 in. at the rear. The brakes also incorporate further refinements:

Aluminum calipers, like the aluminum suspension, reduce unsprung weight.

Electronic brake proportioning. Via the Dynamic Stability Control wheel-speed sensors, the amount of slip at each wheel is measured when the brakes are applied, and pressure to the front and rear brakes is apportioned accordingly. This makes best use of the available braking traction at the tires and helps distribute brake and tire wear more evenly.

Dynamic Brake Control reinforces the driver’s pedal effort in emergency braking, helping the driver achieve the shortest possible stopping distance.

Electromechanical parking brake. As a first in a production automobile, the parking brake is applied electrically rather than directly by human effort. To engage it, the driver presses a button at the left side of the instrument panel.

Automatic Hold, described earlier.

Brake-wear display. Instead of a simple warning indicating that it’s time to renew the brake pads, the iDrive monitor offers in its Vehicle menu a display of the estimated mileage at which replacement of the pads will be due.

iDrive: the new way to command a BMW:
Contemporary automobiles – particularly luxury cars – pose an ever-growing challenge to their designers: how to accommodate the extensive functions that modern technology offers without overwhelming the driver and cluttering the driving environment with controls. iDrive is BMW’s solution.

By dividing the vehicle’s control environment into two areas – Driving and Comfort – iDrive separates those functions that pertain directly to vehicle operation from those that relate more to occupants’ comfort and well being.

The Comfort Zone:
This extensive set of functions, or “secondary zone,” is positioned centrally in the front occupant compartment. Though characterized as the Comfort Zone, actually it encompasses a wide range of comfort, convenience, and informational features and also presents users with some interesting and highly useful choices in how features and functions operate.

Here, BMW has applied the proven concept of the Navigation System that has long been available in various BMW models: a color monitor with menus, and a controller. The main conceptual differences here are that more functions than ever are controlled in this manner, and that the controller is in a central position between the front seats. A further refinement is that the controller incorporates force feedback: According to the functions it is currently controlling, it communicates to the user an appropriate tactile feedback. The controller is equally accessible to the driver and front passenger, and is finished in elegant satin aluminum.

Story by BMW Editing by Maximum-Cars.com