Electric Superchargers - How Audi Is Eliminating Turbo Lag

Posted by: Jeremy Patterson on 11/17/2021

Jason from Engineering Explained is back again with some more knowledge for us, helping explain exactly what’s going on with Audi’s new electric powered compressor. As Jason points out, this is basically an electric supercharger, a compressor wheel driven by a 7kW electric motor instead of being driven by the engine’s crankshaft.

Most of our fellow gearheads can see the benefit of this, as it sort of combines the best aspects of turbocharging (no parasitic loss) and supercharging (boost on demand without lag) into one unit. The system looks to be overly complicated, but as Jason breaks it down, it begins to make sense why Audi chose to do things the way they did.

Looking at the system on his trusty whiteboard, we can see how everything is laid more clearly than looking under the hood, where much of it is covered for aesthetic purposes. There are also some excellent animated graphics from Audi to help illustrate exactly what’s going on as air moves into, through, and out of the engine. I’m not going to walk through it step by step, but you can see the series of valves in the plumbing for the turbo setup that dictates where air flows and which turbos do what and when.

We’re most interested in the electric powered compressor and how that may be used in other applications. This being a smaller displacement engine means it doesn’t require a huge volume of air compared to, for example, a 500+ cubic inch racing engine. But I can’t help but wonder if somebody out there couldn’t convert a ProCharger to electric power to force-feed a racecar air without pulling a couple hundred horsepower from the engine to spin it. It seems like it may be beneficial enough to look into. Perhaps Jason will see this and tackle the math and physics at play and let us know if it’s something we may be seeing on the drag strip soon!