Audi SQ7 debuts electric turbo

AUDI'S new SQ7 high-performance SUV will debut electric turbocharger technology that Audi claims means “turbo lag is history”.

The 4.0-litre V8 turbo-diesel gets two traditional exhaust-driven turbochargers arranged sequentially for a broader spread of power.

But there is also an electric compressor that works at low engine speeds to all but eliminate the lag that makes turbocharged engines feel momentarily sluggish.

The electric turbo – or electric compressor, as Audi refers to it – is fed by a dedicated 48-volt system that can provide up to 13kW of electricity; the electric compressor uses up to 7kW.

The result is 320kW of power and a hefty 900Nm of torque, the latter produced from just 1000rpm, ensuring near-instant access to the torque peak.

Claimed 0-100km/h acceleration is 4.8 seconds and average fuel use is 7.4 litres per 100km.

Helping the efficiency is a tricky Audi Valvelift System that adjusts valve openings depending on engine speed. At low speeds it keeps one of the exhaust valves shut, bringing them into play at higher revs to spin the second of the sequential exhaust-driven turbos.

The engine drives through an eight-speed auto and Quattro all-wheel drive system with a self-locking centre differential designed to maximise traction.

Audi says the combination ensures “extremely dynamic off-the-line performance”.

As with the smaller SQ5, plenty of work was put into making the SQ7’s engine sound good.

There’s a sound actuator that “amplifies the sonorous eight-cylinder sound”, with the driver able to control the level of amplification.

The SQ7 also gets four-wheel steering as part of an optional driving dynamics package that includes a sport differential and active roll stabilisation.

The active stabiliser bars are connected via a three-stage planetary gearbox operated by an electric motor that replaces the more common hydraulic set-up. It means the stabilisers effectively decouple on bumpy surfaces but twist against each other with up to 1200Nm of force to reduce body roll and increase steering accuracy.

The four-wheel steering turns the rear wheels up to five degrees – in the same direction as the fronts at higher speeds and in the opposite direction at lower speeds to tighten the turning circle and make parking easier.

Teamed with air suspension, adjustable dampers and tyres up to 22 inches in diameter, it makes for one of the most driver-adjustable and technologically advanced Audis ever.

The SQ7 is due in Australia in the third quarter of 2016 and is expected to be priced around $180,000.