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World First – The New 435PS Audi SQ7 TDI With Electrically Powered Compressor Technology

By Maddy Price
Thursday, March 3, 2016 - 16:30

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Tapping into extra accelerative power becomes as quick and easy as flicking a light switch this week as the new 435PS Audi SQ7 TDI joins the range as the world’s first series production car combining turbocharging with an electrically powered compressor bringing breathtakingly immediate response. Consigning ‘turbo lag’ to history, the boundary-stretching technology underscores the newcomer’s eligibility for the ‘S’ badge that denotes extraordinary performance across the Audi range, and fittingly goes hand-in-hand with another major forward stride in dynamics – electromechanical active roll stabilisation for significantly reduced body roll.

At the heart of the new Audi SQ7 TDI is a redesigned V8 BiTDI engine that now develops 435 PS and 900 Nm (663.8 lb‑ft) of torque, firmly staking this performance flagship’s claim as the most powerful diesel SUV on the market. The electrically powered compressor dispenses with any sign of turbo lag from step-off acceleration, helping to set an outstanding 0-62 mph sprint time of just 4.8 seconds. Top speed is limited to 155mph, and in the New European Driving Cycle (NEDC), the SQ7 TDI returns up to 38.2 mpg combined. This corresponds to COemissions of 194 g/km.

“Following the launch of the successful SQ5, we are now also applying the concept of a diesel-engined S model to the Q7 model line. So equipped, the SQ7 TDI with a V8 TDI engine achieves the consumption figures of a six-cylinder. The new technology solution of the electric powered compressor in the SQ7 TDI is a world first in the competitive environment, with which Audi once again underscores its claim Vorsprung durch Technik,” said Dr. Stefan Knirsch, Member of the Board of Management of AUDI AG for Technical Development.

Forced induction: Three chargers working together

The 3,956cc 4.0 TDI has been redesigned from the ground up. It combines best-in-class performance with impressive efficiency credentials through the use of two exhaust-gas turbochargers which are activated selectively according to the concept of sequential charging, since exhaust gas only flows through one turbocharger at low and intermediate load. The second turbine is only activated at higher loads. The electrically powered compressor (EPC) augments the work of the two turbochargers, particularly in the lower engine speed range, providing for extremely responsive off-the-line performance.

Forced induction concept and electrical system: Electric powered compressor (EPC) and 48‑volt subsystem

The electrically powered compressor is a world first in a production vehicle. This EPC strongly supports the 4.0 TDI engine when starting off and accelerating from low load for exceptional take-up with no turbo lag. It is placed in the air path downstream of the intercooler, close to the engine. Because the EPC does not require any exhaust-gas energy to develop boost, it can be used at any time, thus making it the solution for the traditional weaknesses of the classic exhaust-gas turbocharger. With this technology, turbo lag is history.

The Audi valvelift system (AVS) is also making its debut in a diesel model from Audi. The inlet and exhaust cam shafts each have two cam contours per valve. On the inlet side, one cam contour supports starting off in conjunction with the EPC, while the other optimises cylinder filling and thus power at high engine speeds. The AVS system on the exhaust side enables activation of the second exhaust-gas turbocharger. The sequential charging system controls the two exhaust-gas turbochargers so that only one turbocharger is used at low engine speeds. The second is activated additionally at higher loads and engine speeds. The customer benefits from very good torque delivery and dynamic response across the entire engine speed range.

V8 TDI – further technical highlights

The intake side of the 4.0 TDI is on the outside, the exhaust side with the two turbochargers is on the inside of the 90-degree internal V. This layout provides for short gas paths, i.e. spontaneous response and short paths for the emissions control system. The common-rail system generates up to 2,500 bars of injection pressure. Ignition pressure reaches the 200‑bar mark in broad sections of the characteristic.

The innovative thermal management and sophisticated measures in the crankshaft and camshaft drive reduce friction. With the combination of a NOx oxidating catalytic converter and a downstream SCR catalytic converter, which is integrated into the diesel particulate filter and uses AdBlue injection to reduce oxides of nitrogen, the V8 TDI has a particularly efficient emissions control system. A sound actuator in the exhaust system amplifies the sonorous eight-cylinder sound and SQ7 TDI drivers can vary the amount of sound it generates using the Audi drive select system.

The biturbo V8 combined with the EPC is a core element of the global Audi diesel strategy. With high torque even at low engine speeds and low consumption figures, it is also ideally suited for markets such as the United States. Its engine characteristic combines supreme pulling power with impressive agility,  exceptional step-off performance and spontaneous response.

High efficiency: The eight-speed tiptronic

The 4.0 TDI in the Audi SQ7 TDI works with strong partners, including a redesigned eight-speed tiptronic which is impressively efficient. It changes gears extremely quickly and efficiently, and at high speeds allows coasting at idle. A self-locking centre differential is the heart of the quattro permanent all-wheel drive system. It is compact, lightweight and interacts very precisely with the suspension control system.

The maxim of lightweight construction also applies to the suspension – its links are made primarily of aluminium. Electromechanical power steering, the Audi drive select driving dynamics system and adaptive air suspension with S-specific tuning are standard. Extremely lightweight carbon fibre-ceramic discs will also become optionally available shortly after the market launch. Audi offers the SUV with 20‑inch wheels on 285/45 tyres, with options up to 22 inches from quattro GmbH available soon after UK ordering opens.

Networked suspension control

Audi offers the SQ7 TDI with an optional driving dynamics package comprising three technology modules: sport differential, electromechanical active roll stabilisation and all-wheel steering. The highly integrated suspension control unit is used in the SQ7 TDI. It assumes the central control of the adjustable shock absorbers, the air springs, the sport differential and roll force distribution. By incorporating all relevant suspension functions into a central control unit, the developers achieved an optimal networking and coordination of the functions among themselves. The customer thus experiences outstanding handling in any situation.

Body roll stabilisation

A new solution in the competitive environment is the optional electromechanical active body roll stabilisation. Here a compact electric motor with a three-stage planetary gearbox separates the two halves of the stabiliser. On an uneven road surface, they are actively decoupled from one another, resulting in improved ride comfort. During faster driving, the tubes are interconnected and twisted against each other. That significantly reduces body roll, i.e. the lean of the car. Together with the transmission, the electric motors produce anything up to 1,200 Nm (885.1 lb‑ft) torque. The effect is taut, precise handling: The car leans less in bends and the tendency to understeer is further reduced. The front and rear stabilisers can be adjusted independently of each other. This active distribution of forces between the front and rear axle has a positive effect on road behaviour. Steering precision and the agility of the car improve significantly.

Compared with conventional hydraulically switched stabilisers, the 48‑volt-based system from Audi offers major advantages. It can develop more power, it works faster and it is activated even at low speeds. Because it requires no oil, the electromechanical active roll stabilisation is also maintenance-free and environmentally friendly.

 

Seven seats as standard

Passengers in the Audi SQ7 TDI experience the largest interior in the segment. The second row has a three-section backrest with segments that can be folded down separately, while the final third row folds up and down electrically.

Interior quality with S-specific design language

More space in the interior sets a new benchmark in the segment. Diffuser vent wrap and application strips emphasize the horizontality and spaciousness of the interior. Comfort features are luxury-class. With the SQ7 TDI, customers have the choice between standard sport seats and optional sport seats plus. The sliding/folding seats provide for easier access to the optional third row. The power tailgate is standard. The SQ7 TDI boasts elegant design solutions in the interior, including analogue instruments with gray faces and white needles, special welcome screens and S badges.

The complete interior lighting including the luggage compartment employs LEDs. The first upgrade level, the lighting package, is standard. Capacitive (contactless) switches control the light in the door pockets and the reading lamp. The instrument panel and door trim contain so-called contour lighting – extremely slender LED light guides that follow the broad lines. Ambient lighting is also available. This includes lighted door sill trims and additional contour lighting on the center console. The top version allows the driver of the SQ7 TDI to customise the interior lighting. Via the MMI, the driver can adjust it in several profiles and in five zones, and regulate the colour of the contour lighting in the ‘drive select’ profile in 32 steps.

The new SQ7 TDI is available in 12 colours. The distinctive radiator grille and underbody guard that encloses the four rectangular tailpipes are finished in twilight grey matt.

High-resolution graphics: Audi virtual cockpit

With its 12.3-inch display, the Audi virtual cockpit presents logically structured information in brilliant graphics. Driver ergonomics are excellent, and operation is intuitive. The driver chooses the display mode via the multifunction steering wheel. A head-up display is also available as an option.

The standard MMI navigation plus with MMI all-in-touch includes a large glass surface on the center tunnel console that provides the finger with haptic feedback after each click. The MMI logic allows for intuitive system operation and also understands terms from everyday speech.

Potent computing power: Infotainment and Audi connect

MMI navigation plus, the top-of-the-line infotainment system in the SQ7 TDI, uses the second-generation Modular Infotainment Platform. Thanks to the integrated LTE module included in the Audi connect package, passengers can surf at high speed with their mobile devices. The Audi connect package (3 month trail is std with the option to extend)  brings comprehensive online functions on board.

New on the market is the Audi connect safety & service package, which also includes the myCarManager package. With this, customers can use their smartphone to lock and unlock the car or check the vehicle status, for example.

Another infotainment highlight is the Audi smartphone interface. In the car, a tailored environment on the MMI monitor makes it easy to control smartphones with iOS or the Android operating system.

Two optional sound systems in the SQ7 TDI are as innovative as they are upscale. The Bose Surround Sound system, which generates the surround sound with 19 speakers, also features two speakers located higher up in the A-pillars to produce the third dimension. In the Bang & Olufsen Advanced Sound System, the digital signal processor drives 11 channels with a total of 23 speakers in such a way that the sound is equally precise and harmonious in every seat. Four speakers installed in the A‑pillars and driven via separate channels broadcast those elements that generate the spatial height, creating a big virtual stage. Newly developed speakers and an amplifier with 1,920 watts guarantee musical enjoyment at the highest level.

Array of optional  driver assistance systems

The SQ7 TDI offers a wide range of 24 driver assistance systems to help drivers travel safely, fuel-efficiently and comfortably. The predictive efficiency assistant, for example, provides additional information in the instrument cluster to help the driver save fuel. The standard Audi pre sense city – an anticipatory warning and emergency breaking function for avoiding accidents and protecting pedestrians – makes the SQ7 TDI even safer.

Adaptive cruise control with traffic jam assist relieves the driver in slow-moving traffic on well-paved roads by taking over the steering in many situations. The predictive ACC enables the anticipatory adjustment of driving speed to the route and speed limits, such as when entering towns.

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