Combination Supercharger and Turbocharger for VW Golf GT
By Mike Hanlon
September 15, 2005
At the International Motor Show (Cars) in Frankfurt, Volkswagen is presenting to the general public a groundbreaking innovation in the drive sector: The world’s first twinturbocharged FSI engine – the “Twincharger”. The compact 1.4 litre direct-injection engine develops 125 kW / 170 PS and has a maximum torque of 240 newton metres in the range from 1750 to 4500 rpm thanks to the combination of an exhaust turbocharger with a mechanically driven compressor. Furthermore, the “Twincharger” delivers a torque corresponding to a naturally aspirated engine of approximately 2.3 litres. And its fuel consumption is around 20 percent lower.
Diversified industrial manufacturer Eaton Corporation partnered with Volkswagen to help produce the combination supercharger and turbocharger system. The twincharger system combines a half-size, Eaton Roots-type supercharger with a single-stage turbocharger on VW's new TSI 1.4-liter gasoline engine, which replaces the FSI engine previously available on the Golf in Europe. The system boosts the four-cylinder engine to 168 horsepower and 177 lb-feet of torque at an impressive fuel consumption average of 39.2 mpg.
"This system really is a best-of-both-worlds scenario: two technologies carefully crafted into a system that helps Volkswagen answer European consumers' demands for performance and fuel efficiency in one cost-effective package," said Jeffrey Romig, vice president and general manager, Eaton Air Induction and Cylinder Head Systems.
By combining the performance-enhancing elements of supercharging and turbocharging, a customer realizes the benefits of both technologies. The belt-driven supercharger compressor provides high torque at low engine speeds. The turbocharger kicks in to provide added performance at higher rpms. When the turbo system reaches ideal speeds, the supercharger is declutched and an electronically controlled bypass valve directs air to the turbocharger, which delivers high-end power without the "lag" generally associated with turbocharging.
The combination system allows an automaker the option to provide a smaller displacement gasoline engine while improving performance, and reducing fuel consumption and emissions. The system is an evolution of Eaton's long history of innovation in engine air management, primarily in supercharging. In addition to boosting performance, automakers are also using superchargers to assist with meeting fuel economy and emission requirements in gasoline engines. In Europe, forecasts show that 70% of gasoline engines will be equal to or less than the 2.0-liter size. These lower displacements will require boosting to maintain performance, drivability, and emissions compliance.
The new system will be supplied from Eaton's facility in Tczew, Poland with production expected to ramp up in September. The 2006 Golf GT goes on sale this fall and Volkswagen will use a variation of the TSI engine in future European models including the Touran compact MPV.