Garrett Advancing Motion, a leading supplier of turbochargers, on Thursday announced it will launch an electrified turbocharger designed for mass-produced cars by 2021.
Garrett's design for its electrified turbo, dubbed an E-Turbo, is similar to the MGU-H design used in Formula One.
The E-Turbo features an electric motor-generator mounted to the shaft connecting a turbo's compressor wheel and turbine. The motor-generator actually sits in between the compressor and turbine in Garrett's design.
At low revs—we're talking just off idle—the motor spools up the turbo to provide compressed air, known as boost, thus eliminating dreaded turbo lag (the moment before the spike in power experienced in turbocharged engines). It also means that a larger compressor wheel, which takes longer to spool up than a smaller wheel but provides more boost, can be added.
But there's another benefit. The motor can also act as a generator, turning heat energy normally wasted in the exhaust into electricity. This electricity can then be stored for later use, including powering the wheels.
Mercedes-AMG was the first to announce an electrified turbo for a production car, in this case in the One hypercar that's still in the works. Infiniti has also promised the technology for its Q60 Project Black S, although the high-performance coupe hasn't been confirmed for production just yet.
Mercedes-AMG One prototype
There's a similar technology already available. French supplier Valeo come out several years ago with an electric compressor, with the first application being the Audi SQ7 TDI. Designed for turbocharged engines, Valeo's electric compressor is a standalone unit that uses an electric motor to spin a compressor wheel and develop boost at low revs. While it also eliminates turbo lag, it doesn't have the ability to regenerate energy like Garrett's design.
According to Garrett, it's E-Turbo at low revs, specifically 1,500 rpm, is able to deliver a targeted torque rating in 1.0 second versus the 4.5 seconds that a conventional turbocharged enigne requires. In Garrett's own testing, that translates to 25 percent quicker acceleration from 37 mph to 62 mph—perfect for those highway merges.
Garrett said the E-Turbo will innitially appear in premium, high-performance cars but will eventually filter down to mainstream cars.