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Wednesday / 8 December 2021
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Electric supercharging – How it works

Electric supercharging is one of the newest ways to draw more power out of an engine, and is generally used alongside turbochargers to assure constant boost throughout the rev ranges.

Contrary to how it might sound, these components are not used to enhance an electric engine’s performance – but rather to use an electric motor to enhance the performance and lower the emissions of an internal combustion engine (ICE).

How it works

According to BorgWarner, one of the first developers of the electric supercharger (eBooster), an eBooster is a turbine-based flow compressor that is driven by a 12V or 48V electric motor.

The eBooster is placed either before or between a turbo and an engine in order to intercept weak air flow, and connects directly to the throttle so that its fan can spin at a rate that is proportional to the pressure on the pedal.

Air is channeled to the eBooster via an opened or closed valve. In turn, the electric motor initiates and rotates a turbine to compress and accelerate the air either into the turbo, or from a turbo into an engine to increase output.

These set-ups are mostly used to minimise the occurrence of turbo lag, as the eBooster activates at low airflow volumes where a turbo has not yet started to provide boost.

As a turbo needs time to spool up and generate power, there is a short amount of time where a vehicle feels unresponsive as you are waiting for the boost to kick in.

In addition to mitigating turbo lag, eBoosters can provide an extra jolt of instantaneous power in certain situations.

For example, in the new Audi SQ7, a 48V electric supercharger spools up to 70,000 rpm in a matter of milliseconds and adds 7kW of instantaneous boost.



eBoosters are usually found on more expensive cars and installed directly at the factory.

While there are plenty of aftermarket eBoosters on offer, average consumers should be weary of fitting their own.

These eBoosters are often advertised as affordable “plug-and-play” solutions to eliminate turbo-lag and improve performance, but can be hand-sized components that do not create a strong enough airflow to have any real effect on the engines they are connected to.

Benefits and drawbacks of eBoosters

The main benefit of eBoosters, according to BorgWarner, is the reduction of turbo lag in vehicles with large engines.

Furthermore, these parts reduce emission levels and fuel consumption, due to the more efficient delivery of power.

eBoosters will also make the constant downsizing of engines easier to manage, with companies actively looking at withdrawing V12, V10, and V8-size engine from their ranges.

The main drawback of eBoosters are the cost.

The technology is still in its infancy and is expensive to develop and install.

Therefore, it will take some time to become more readily available in everyday vehicles with smaller motors.

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