• The new Ford Shelby GT 350 will feature a naturally aspirated 5.2L engine delivering more than 500 hp (373 kW), or approximately 75 kW/L. The 2014 Ford Shelby GT500 is powered by an aluminum 5.8-liter supercharged V8 producing 494 kW (662 hp) and 856 N·m (631 lb-ft) of torque, or 85 kW/L and 148 N·m/L.

• The 2016 Corvette Z06’s features an LT4 supercharged 6.2L (6162 cc) V-8 engine, which is SAE-certified at 650 horsepower (485 kW) at 6,400 rpm and 650 lb-ft of torque (881 N·m): 79 kW/L and 143 N·m/L.

• The 2015 Dodge Challenger SRT Hellcat’s supercharged 6.2-liter (6,166 cc) HEMI V-8 engine is rated at 707 hp (527 kW) and 650 lb-ft (881 N·m) of torque: 85 kW/L and 143 N·m/L.

• The new Mercedes-Benz AMG GT S with 4.0L (3,982 cc) biturbo delivers 375 kW (510 hp) and 650 N·m (479 lb-ft): 94 kW/L and 163 N·m/L.

Audi’s electric biturbo combines a conventional gas-driven turbocharger with a secondary electrically driven compressor; in exterior appearance it is almost identical to that of a conventional turbocharger.

Turbochargers are typically driven by energy from the exhaust—i.e., starting from very low revs, the rise in boost pressure and therefore torque becomes gradually greater only as the exhaust energy increases. The electric biturbo, by contrast, makes it possible to build up charge pressure quickly and achieve high levels of torque even at very low revs.

Thus, an electrically powered compressor can offers significant advantages: It revs up to maximum rpm rapidly and without any perceptible delay, and it continues to boost charge pressure when too little drive energy is left in the exhaust gas for the conventional turbocharger.

This operating principle makes it possible to design the conventional turbocharger more specifically for high charge pressures and consequently for high engine power—the e-turbo assures spontaneous response and powerful sprints from low engine speeds at all times.

In the lower engine speed range, the electrically driven compressor boosts torque by up to 200 N·m (147.5 lb-ft). A dedicated 48‑volt electrical sub-system—another key future technology from Audi (earlier post)—supplies electrical energy to the turbocharger. A compact lithium-ion battery in the luggage compartment stores the energy that is generated by recuperation when coasting. A DC/DC converter provides the connection to the 12‑volt electrical system.

The electrically driven compressor lets the TT show car cover up to 16 meters (52.5 ft) within the first 2.5 seconds—which is six meters (19.7 ft) further than a comparable car without this innovation.

The electric biturbo signifies a new dimension in driving enjoyment; it boosts sprinting ability and torque and enables high peak power. In our TDI engines, we are close to production readiness with this technology. We are now presenting it in a TFSI – here too, we are the first automaker in the world to do this. For our fans at Wörthersee, we have packaged the electric biturbo in a very sporty show car.

—Prof. Dr. Ulrich Hackenberg, Audi Board Member for Technical Development

Thanks to systematic lightweight design, the TT clubsport turbo show car has an unladen weight of just 1,396 kg (3,077.7 lb). The car completes the standard sprint from 0 to 100 km/h (62.1 mph) in 3.6 seconds, and its top speed is 310 km/h (192.6 mph).