AMG’s new electric turbocharger eats lag for breakfast

By topgear, 22 June 2020

You may have noticed that there’s been a trend of ‘downsizing’ (the mass adoption of replacing big naturally-aspirated engines with smaller turbocharged ones) over the last few years. It was a forced hand by the rule-makers to reduces fuel consumption and, in turn, CO₂ emissions. People booed and hissed at this move, but one company that has shown that downsizing doesn’t need to be the devil’s work is AMG.

Its history was built on naturally-aspirated V8 excellence, but in recent years the company has proved that you can downsize, add turbos, increase efficiency and still deliver an apocalyptic soundtrack and blistering speed. One side effect of all this turbocharging though, is lag. Which is bad. Well, was bad. Mercedes-AMG is out to make it a thing of the past thanks to this new, trick electric turbocharger.

Mercedes will now use an electric motor to keep the turbo spinning, even at low RPMs when the exhaust gases are low, to increase response and further reduce emissions. The 4cm electric motor (powered from the onboard 48v mild hybrid system) is integrated directly on the charger shaft (between the turbine wheel on the exhaust side and the compressor wheel on the fresh air side), whirs into life when the exhaust gases reduce to keep the turbo spinning up to 170,000 rpm; even when off throttle or on the brakes. This means that when you pick the throttle back up again, you have maximum performance from the turbo, and zero lag. So think of it as an electronic anti-lag system.

AMG states this F1-derived technology “will be used for the first time in a series-production model from Affalterbach” - could it be on the upcoming AMG GT Black Series? We’ll just have to wait and see. Until then, read our guide to turbocharging a car, though, try not to blow your engine up. It happens.