The automotive industry is in a flux of transformation, wherein brands are looking for replacement over displacement and advancing their already-existing technology for better performance and efficiency. A case in point here is e-Turbo, the technology evaluated and developed on racetracks, which is dubbed as similar to the MGU-H unit in Formula-1 cars. Once exclusive to race cars will soon be democratized in road-legal cars that are expected to overcome the drawbacks of conventional turbochargers. E-turbo packs a lot of potential to be soon used in modern-day cars by enhancing fuel efficiency from an even smaller engine, as this technology not just eliminates turbo-lag but also enhances energy recovery.
To understand e-turbo, we must revise what a turbocharger is and how it functions. In layperson's terms- a turbocharger is a device that forces more air into the engine to produce more power and efficiency. Turbochargers use the engine's hot exhaust gas to spin an inlet turbine, which then drives the compressor, thus pushing more air into the combustion chamber to make fuel burn properly, thus generating more power and better fuel economy. But there is one significant drawback to the conventional turbochargers - TURBO-LAG. Turbo-lag is nothing but the time taken by the turbines inside the turbos to spool up. It takes time to match the revving speed to create enough exhaust pressure to spin the turbo to its maximum efficiency. Time delay is the longest when the engine is in a low-rpm and under a low-load cruising situation. Another flaw with this system is that the engine monitors the optimum amount of exhaust air into the chamber, and the excess exhaust gas energy is prone to waste.
Well, both of these shortcomings of a conventional turbocharger can be solved with the help of an e-Turbo. However, this technology is currently quite expensive and complex for now. But it will surely be put to use as it eliminates turbo lag and can store waste energy in the form of electricity. Moreover, with the strict emissions norms and taxation structure, engine downsizing will be prominent and hence to extract maximum power out of the engine, e-turbo will be a prominent way out.
Well, nothing rocket science. An E-turbo is like a typical turbocharger with a motor attached to the turbine shaft. Because of electric motors, turbochargers no longer depend on exhaust gasses to spin the turbine at low rpms. The turboshaft gets active, compresses air with the throttle inputs, and forces air into the engine with minimal turbo lag. The second major benefit of the e-turbo is the polarity of the motors. A motor can spin in two directions and act as a generator when spun in reverse, thus able to harness energy. And in hybrid vehicles, the harnessed energy can be further put to use. Apart from regenerative energy, energy generated due to E-turbo can be harnessed into a capacitor, just like how the F1 KERS system works. Because of e-turbo, hybrid cars can use a bigger battery to give them more electric range without compromising performance.
Mercedes-Benz has partnered with Garrett Advancing Motion for the e-turbo technology in the Mercedes-AMG C43 sports sedan. The engine used in C 43 is a mild hybrid, 2.0-litre four-cylinder turbocharged. The engine is rated to produce 402 horsepower with the ability to boost output using the 48-volt hybrid motor/generator by 13 hp for a total peak power of 415 hp. In comparison, the same basic M139 engine with a conventional turbocharger with no e-turbo is rated at 382 hp.
Surely, the potential of e-turbo is inevitable; sooner than later, it will make its way into mainstream cars as well. Craig Balis, Garrett's chief technology officer, also believes, "Electrified hybrid powertrains are the fastest-growing segment in the industry, projected to grow to more than 40 percent of all vehicles in the next five to ten years."
To democratise e-turbo technology into mass-market cars will follow soon as it proves its benefits in performance cars, which is about to happen in the near future. Auto manufacturers have tied hands with technology companies such as BorgWarner and Garrett Advancing Motion to develop e-turbo technology. It is then just a matter of time before we witness another advancement in the powertrains of our cars. With the EVs taking over, the interim solution from e-turbo will revive internal combustion with more performance and better efficiency.