I always used to laugh at the idea of an electric turbocharger as it always brought to mind something like this:

http://www.amazon.com/Air-Intake-Sup.../dp/B004N8W31O

But as we know Audi has been working on the electric turbocharger and it is now confirmed as a supplement to the TDI to help provide boost immediately.

http://www.leftlanenews.com/audi-con...7-in-2016.html

-Rich

Click here to enlarge Originally Posted by Leftlanenews
Audi has confirmed that its electric turbocharger will make its way from prototype vehicles to a production model by 2016, helping improve performance for the upcoming SQ7 TDI.
The company last month promised the technology would make its way to the market in the near future, fueling speculation that the RS5 TDI might be first in line. Technical director Dr. Ulrich Hackenberg has doused cold water on such hopes, though the company has not ruled out the RS build for future consideration.

"The new Q7 will be available in the market next year but the electric turbo will come a bit later in the Audi SQ7 available in 2016," hackenberg told Autocar.

The executive did not delve into more detail, but he is believed to be referencing a TDI variant that will take inspiration from the smaller SQ5 TDI crossover.

The company previously showed off an A6 TDI concept that adds an electrically-driven turbocharger, downstream from the traditional turbo, that ramps up to full boost nearly instantaneously at low rpm. As the exhaust begins to provide enough flow to drive its own impeller, the system bypasses the electric system and benefits from the higher boost of the traditional turbocharger.

Output specs for the production edition remain unclear, though the SQ5 TDI uses two traditional turbochargers to produce 313 horsepower and 479 lb-ft of torque from its 3.0-liter V6 mill.

Audi appears to view the technology as a more significant jump in the diesel realm, however the company is also considering implementations in gasoline engines to help eliminate lag.
-Rich