New E-Turbo can achieve optimal air-fuel ratio
Hybrid and electric technology are really the ways that will change the global auto industry; and we're not just talking about major markets as even South East Asia is already undergoing that paradigm shift as diesels fall out of favor.
But while we expected hybrid electric tech to be instrumental in transforming how power is sent to the wheels, what we didn't expect was how the same technology can be applied to how the actual engine produces power.
Garrett, the company that tuners know for producing turbochargers, has applied electrified technology to their primary product for generating boost.
Garrett calls it the E-Turbo, and as the name implies, it has been integrated with an electrical unit that can help improve how an engine performs. The company says that the E-Turbo technology is an “electrified boosting solution” that works to “increase engine power and torque”. The solution that Garrett was going for was to improve overall combustion efficiency, and that can be understood by explaining how a turbo works.
A standard turbo is usually an all-metal unit; there is a scroll tube that takes hot, fast exhaust gases and lets them spin a turbine, which in turn spins an impeller to suck in air from the filter and forces it into the engine to boost its power. Some manufacturers use an intercooler to cool the air beforehand (cooler air = denser air = more power), but generally, that is the principle.
The issue lies with the fact that the efficiency of the turbo depends largely on the speed that the turbo spools up. At low RPMs, the turbo isn't working at its best because of the reduced exhaust gases, though some companies compensate for that using a turbine with vanes that alter their angles to generate more consistent boost at those RPMs. Some even use a more expensive sequential turbo set up to achieve the same.
What Garrett did was integrate a 48-volt electric motor unit into the turbocharger that can drive the intake impeller to enhance forced induction at low RPMs. Effectively, the turbocharger almost has an integrated supercharger-like component inside thanks to the E-Turbo system.
Garrett's solution also allows the E-Turbo to function like a smaller self contained hybrid drive system wherein the motor can recover kinetic energy to recharge its own batteries and provide boost when needed later on.
Garrett says they can achieve 16% more power and 10.5% more torque. The E-Turbo system is touted as being able to make torque delivery more consistent along the RPM range. The company also says the system helped achieve better overtaking (60-100 km/h) and better torque for uphill climbs.
The company used a 2.0L petrol Audi Q7 and Jaguar F-Pace. In the Jaguar (presumably a diesel), they combined the E-Turbo technology with a variable turbo. Based on the charts, torque increases almost immediately when the E-Turbo kicks in at 1500 rpm. Garrett says the torque gradient goes up 4 times compared to standard systems.
The innovation with the E-Turbo system is quite interesting because it's geared towards achieving far more stringent emissions standards which require a 15% reduction in CO2 by 2020, as well as a 37.5% drop in 2030 (compared to 2020's numbers). The reason they say E-Turbo can help achieve this is because it can stabilize the air/fuel ratio of the vehicle, allowing it to operate at a constant Lambda 1 across the rev range.
Running at Lambda 1, in car terms, is ideal: it's the stoichiometric air/fuel ratio, meaning perfect combustion and maximum efficiency.
Garret is working on three variants of the E-Turbo GTX system, depending on application: the GT15-17 48V which can be used on vehicles with 1.2L to 1.5L petrol engines and 2.0L diesels, the GT22-30 48-400V which is applicable for 2.0L to 3.0L petrol engines and 3.0L diesels, as well as a GT35-45 400-700V for larger vehicles.
Sources say that the new system will go into production by 2021.