Honeywell Turbo Technologies (Torrance, CA; http://www.honeywell.com/sites/ts/tt) has developed the third generation of its Garrett Variable Nozzle Turbine (VNT) turbocharger, which is said to provide improved boost response by adjusting the gas-flow cross section at the inlet of the turbine wheel to optimize power with load. At low engine speed and low gas flow, the vanes of the VNT close, thereby reducing the inlet area to the turbine, resulting in an increase in turbine inlet pressure, which increases turbine power and drives higher engine boost pressure. At high engine speeds and load, the vanes open, thereby increasing the turbine inlet area. This has a combined effect of preventing over-boost and reducing engine outlet pressure for improved fuel economy at high load operating condition. Information for the required settings of the vane position is provided by another Garrett technology, Rotary Electronic Actuator (REA). Combined, VNT with REA delivers 30% more boost at just 90% of the back pressure as compared with the previous-generation system.
Hyundai Motor Co. (www.hyundai-motor.com) selected this system for its 2.0-liter, four-cylinder diesel engines after Honeywell proved it could provide a 20% increase in peak power and torque with a 1,000-rpm increase in engine range with no degradation of average fuel economy. The system will be installed starting in 2008 and is scheduled to run through 2012.
Additionally, Hyundai will be installing dual-stage turbos on its 2.2-liter diesel engine slated to be used in the replacement for its Centennial sedan, which marks the first time this technology is being used on an Asian luxury car.
While Hyundai says it plans only to sell diesel-powered cars in the Asian market, changes in the U.S. fuel and emissions regulations could make those products viable for the U.S. market.