BorgWarner has revealed some of the details behind its regulated two-stage (R2S) turbocharging technology that has been put to use in Volkswagen’s new 2-liter twin turbo diesel engine.
The engine is the most powerful four-cylinder, turbocharged, direct injection engine ever offered by Volkswagen, with an output of 243ps and a maximum torque of 500Nm. Installed in the new Passat, the twin turbo achieves an average fuel economy of 5.3l/100km and is paired with four-wheel drive as standard.
BorgWarner’s R2S system consists of two series-connected turbochargers and features a variable turbine geometry turbocharger for the high-pressure stage, combined with a larger B03 water-cooled turbocharger optimized for low-pressure exhaust gas recirculation.
As the engine speed increases, both turbochargers work together, gradually shifting to the larger, low-pressure turbocharger. At higher engine speeds, all of the gases flow directly to the larger B03 turbocharger, maintaining smooth power delivery at higher speeds. By combining two series-connected turbochargers of different sizes, BorgWarner says its technology provides high-boost pressures over the entire engine speed range.
President and general manager of BorgWarner Turbo Systems, Frédéric Lissalde, said, “We are pleased to expand our long-term partnership with the Volkswagen Group by delivering our regulated two-stage turbocharging technology for this powerful, downsized diesel engine.”
July 30, 2015