Turbochargers are fantastic pieces of engineering. They take the residual energy from an internal combustion engine and transform it into additional power, with very little loss of efficiency. The problem, historically speaking, is that turbochargers had to choose between being small and reactive but limited in terms of power, or large and offset, but capable of producing enormous power.
There have been several attempts to eliminate this compromise over the years, with devices such as sequential turbos and even double charging (which combines a compressor and a turbocharger) that have had limited success, but at high cost and cost. increased complexity. Now, thanks to its crazy success in Formula 1, Mercedes-AMG thinks they have a new solution: an electric motor, but not like the one you think of.
“We have clearly defined our objectives for an electrified future. To achieve them, we rely on discrete and highly innovative components and assemblies. With this approach, we strategically complement our modular technology and adapt it to our performance requirements,” Tobias Moers, chairman of the board of Mercedes-AMG, said in a statement. “In a first step, this includes the electrified turbocharger – an example of the transfer of Formula 1 technology to the road, something with which we will bring turbocharged combustion engines to a level of agility previously unattainable.”
This sectional drawing shows how the electric motor is actually integrated into the central section of the turbocharger. Mercedes-AMG
Now, most of you have probably seen the wacky plastic “electric superchargers” that you can buy at sketchy online stores, but that’s not it. Mercedes’ system uses a custom electric motor capable of bringing the wheel of the turbocharger closer to its operating speed of 170,000 rpm without waiting for the exhaust gases to do the job.
One of the other advantages of this electric motor system is that even when the car is stopped and the driver has his foot on the brake, the turbo can be kept at speed, so there is no delay in the acceleration when lying on the thin pedal to the right. The system can even use the electric motor to recover energy, in the same way that regenerative braking works on electric cars.
Of course, keeping an electric motor bolted to a turbocharger – not to mention the other sensitive electronic devices needed to operate this system – living in this hellishly hot environment requires special attention. To help improve the longevity of the system, everything is water-cooled, including electronics.
Mercedes has confirmed that the first engine to use this technology will be the four-cylinder M139 – the hottest version of which will be produced. This new turbo-electric system won’t add power per se, but it should go a long way in making that tiny 2.0-liter dread of an engine much more sensitive.