GM Powertrain has a couple of interesting developments for prospective purchasers of Chevrolet Silverado HD and GMC Sierra HD pickups.
That would a new 6.6-litre Duramax 6600 turbodiesel V-8 (RPO LBZ) for later in the 2006 model year, delivering 360 hp at 3,200 rpm and 650 lb-ft of torque at 1,600 rpm, and a new Allison 1000 six-speed automatic transmission with "range selection mode."
Along with that, GM says that all 2006 Duramax engines have been significantly revised to deliver lower emissions and significantly improved quietness and smoothness in every application.
But the big news for people looking for trucks to perform some serious hauling is undoubtedly the new Duramax-Allison combo.
Charles Freese, GM Powertrain executive-director for diesel engineering, says the upgrade to the Duramax diesel sets a new "benchmark to which all others will be measured," just as the engine did when it was unveiled in 2001, leading to a significant increase in GM's share of the diesel pickup market.
Freese explains that the Duramax 6600's horsepower and torque increase and emissions reduction are enabled by a strengthened iron cylinder block and a lower compression ratio.
"The lower compression reduces stress on the engine by reducing the peak cylinder firing pressure," he says. "This, in turn, allows more fuel to be burned -- more fuel means more power -- while the lower compression helps reduce NOx emissions. Lower compression also helps reduce noise and vibration, making the all variants of the 6600 a quieter and smoother engine."
A revised variable-geometry turbocharger also enhances the driving experience of the Duramax 6600, Freese says. "Aerodynamic changes to the turbo's vanes help tailor controlled application of turbo power for seamless and immediate response at full throttle. The turbo, which spins at up to 120,000 rpm, is high-speed-balanced, reducing vibration and resonance -- and contributing to the engine's overall smoothness and refinement. The revised turbo also helps reduce emissions, while maximum boost remains at 20 psi."
The comprehensive list of changes and upgrades to the 2006 Duramax 6600 includes:
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| 6.6-litre Duramax 6600 turbodiesel V-8 (RPO LBZ) and Allison 1000 six-speed automatic transmission (photo: General Motors) |
Along with that, GM says that all 2006 Duramax engines have been significantly revised to deliver lower emissions and significantly improved quietness and smoothness in every application.
But the big news for people looking for trucks to perform some serious hauling is undoubtedly the new Duramax-Allison combo.
Charles Freese, GM Powertrain executive-director for diesel engineering, says the upgrade to the Duramax diesel sets a new "benchmark to which all others will be measured," just as the engine did when it was unveiled in 2001, leading to a significant increase in GM's share of the diesel pickup market.
Freese explains that the Duramax 6600's horsepower and torque increase and emissions reduction are enabled by a strengthened iron cylinder block and a lower compression ratio.
"The lower compression reduces stress on the engine by reducing the peak cylinder firing pressure," he says. "This, in turn, allows more fuel to be burned -- more fuel means more power -- while the lower compression helps reduce NOx emissions. Lower compression also helps reduce noise and vibration, making the all variants of the 6600 a quieter and smoother engine."
A revised variable-geometry turbocharger also enhances the driving experience of the Duramax 6600, Freese says. "Aerodynamic changes to the turbo's vanes help tailor controlled application of turbo power for seamless and immediate response at full throttle. The turbo, which spins at up to 120,000 rpm, is high-speed-balanced, reducing vibration and resonance -- and contributing to the engine's overall smoothness and refinement. The revised turbo also helps reduce emissions, while maximum boost remains at 20 psi."
The comprehensive list of changes and upgrades to the 2006 Duramax 6600 includes:
- cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased horsepower and torque
- upgraded main bearing material increases durability
- revised piston design helps lower compression ratio to 16.8:1 from 17.5:1 -piston pin bore diameter increased for increased strength
- connecting rod "I" section is thicker for increased strength
- cylinder heads revised to accommodate lower compression and reduced cylinder firing pressure
- maximum injection pressure increased from 23,000 psi to more than 26,000 psi
- fuel delivered via higher-pressure pump, fuel rails, distribution lines and all-new, seven-hole fuel injectors
- uel injectors spray directly onto glow plugs, providing faster, better-quality starts and more complete cold-start combustion for reduced emissions
- improved glow plugs heat up faster through an independent controller
- revised variable-geometry turbocharger is aerodynamically more efficient to help deliver smooth and immediate response and lower emissions
- air induction system re-tuned to enhance quietness
- EGR has larger cooler to bring more exhaust into the system
- first application of new, 32-bit E35 controller, which adjusts and compensates for the fuel flow to bolster efficiency and reduce emissions