Large pickups are extremely popular in the US. Vehicles of this kind require high-performance engines that guarantee traction in any situation. A good example of this is the new Duramax V8 turbodiesel from General Motors. BorgWarner supplies an advanced VTG turbocharger and innovative cold-start technology for this engine.
T he unit has a displacement of 402 cubic inches (6.6 liters), maximum power output of 438 hp (327 kW) and maximum torque of 910 lb-ft (1,234 Nm). To put these numbers into perspective, the kind of performance you could expect to find in a heavy truck actually powers the heavyweights among the latest US pickups: the Chevrolet Silverado and the GMC Sierra, each available as a 2500HD and 3500HD version. HD stands for heavy duty in this instance. The new engine has absolutely no trouble living up to this name – at very low revs and with fuel consumption and emissions values that are significantly improved over its predecessor.
Power with precision
Close cooperation between the teams of developers at GMC and BorgWarner resulted in a turbodiesel unit that sets completely new standards for diesel engines in the heavy pickup segment. The new power diesel delivers 12 percent more power and 19 percent more torque – the latter of which is now available from just 1,600 rpm. This impressive engine performance is largely thanks to an electronically controlled VTG turbocharger (variable turbine geometry) from BorgWarner.
The system in question is a turbocharging system with newly developed impeller wheel and a new turbine vane design which has been dimensioned to handle exhaust gas temperatures of up to 820 °C. The electronic adjustment of the turbine vanes guarantees optimum matching of the exhaust gas stream to the respective operating point of the engine, which significantly improves the response at low revs and the transient response. During braking, the turbine vanes are closed, thereby increasing the exhaust back pressure and allowing the engine to develop maximum braking force. Overall, the turbocharger was specifically developed to increase the power, control and durability of the drive when transporting and hauling heavy loads and thereby to optimize both efficiency and emission values. The new turbocharging system is produced at an ultra-modern manufacturing facility in Asheville, which has been set up to deliver maximum quality and efficiency while producing in large numbers.
Low cold-start emissions
The cold-start system from BorgWarner makes a contribution to reducing exhaust gas emissions. Even at outside temperatures as low as -29 °C, the ceramic glow plugs reach temperatures of up to 1,000 °C within two seconds. The control module of the glow plugs regulates the voltage separately for each individual glow plug, ensuring that the right temperature is available at all times, thus optimizing the combustion process. The turbodiesel warms up faster, burns less fuel and produces lower emissions.
Besides the turbocharging system and the cold-start technology for the new GM models, BorgWarner also supplies the electronically controlled fan drives for the Duramax engine and friction plates for the Allison 1000 automatic transmission. With the successful completion of the development projects for General Motors, BorgWarner was once again able to demonstrate its full-scope expertise in the drive sector.
Gets things moving even from low revs:
the VTG turbocharger from BorgWarner.
Photo: © BorgWarner