Garrett Motion has confirmed it’s developing an ’E-Turbo’ for mass market passenger vehicles, which is expected to launch in 2021.
The announcement comes as automakers turn to electrified engine technology that meets industry challenges for increased energy efficiency and new regulatory emission targets while still meeting consumer demands for better vehicle performance and affordability. While Garrett’s first E-Turbo application will emerge in premium, high-performance vehicles, Garrett has 10 active programs in the three biggest auto markets in the world in varying vehicle segments.
Turbochargers use otherwise wasted exhaust energy that would go out the tailpipe to drive a turbine wheel connected via a shaft to a compressor wheel. The compressor wheel packs more air into the engine yielding the now familiar “turbo boost” to vehicle acceleration. This has allowed automakers to use smaller, more efficient engines helping to improve fuel efficiency and reduce carbon dioxide emissions without compromising performance.
Garrett’s E-Turbo keeps this basic concept but adds a small electric motor on the shaft between the two wheels, which allows two new things to happen. First, the electric motor can spool up the turbo to provide boost immediately off idle, effectively eliminating the lag between the time a driver hits the accelerator and felt acceleration. Electrifying the turbocharger also removes the design constraints prioritizing turbine efficiency at low engine speeds to drive the compressor. The addition of electric power to compensate when air flow is low allows Garrett to use a larger turbo more appropriately matched to engine’s natural sweet spot of operation.
Second and most exciting to the future of hybridization across vehicle segments, the E-Turbo can electrically recuperate spent –and otherwise wasted–exhaust energy by using a small electric motor to generate electricity and recharge the hybrid battery. This ability to be an onboard provider of electricity opens up options for auto makers in designing hybrid powertrains.