The first Continental turbocharger with its RAAX turbine technology has now entered production on Audi’s new 2.0-litre turbocharged gasoline engine (2.0l TFSI EA888, generation 3B).
The RAAX name stands for “radial-axial”, and is something that Continental states is the most important innovation on the unit. Unlike the most common type of gasoline turbocharger today, the radial turbocharger, which features a radial exhaust gas inlet, the new Continental turbocharger has a radial-axial (semi-radial/semi-axial) inlet path. The associated special blade design allows a substantial reduction of approximately 40% in the rotational moment of inertia of the turbine wheels. This means the turbocharger responds faster to engine load changes, so boost pressure is developed more quickly and turbo lag is minimized. In addition to this significant improvement in response, RAAX technology also results in up to 3% greater efficiency in the engine relevant operating range, leading to reduced emissions.
An innovative solution has also been implemented for the wastegate valve, which prevents boost pressure from rising too steeply at high engine output. Here the turbocharger team was able to leverage internal synergies, because Continental’s existing technology portfolio already features an electronic wastegate control system noted for its high reliability. In the new turbocharger, the wastegate actuator system has been adapted to provide a very robust solution for the actuator/wastegate linkage.
“Our RAAX turbocharger sets the standards today for both thermodynamics and transient response,” said Udo Schwerdel, head of Continental’s Turbocharger Product Line. “This is also coupled with robust design and high quality, which are always a top priority in our development projects. These high quality standards are further underpinned by our standardized, state-of-the-art production methods, which we will be adopting at our new manufacturing sites too.”
At present, Trutnov in the Czech Republic is Continental’s sole manufacturing site for the new turbocharger, but a further facility is already under construction in China. “From 2017, this plant will manufacture turbochargers for a number of volume production projects”, said Schwerdel. “Another facility is also under construction in North America. Production orders are already lined up for this new plant too, which is due to open in 2018.”
June 24, 2016