THE C7 ERA: 2014-2019 continued
Supercharged, efficient performance The heart of the 2015 Corvette Z06 is the all-new LT4 6.2L supercharged V-8 engine, expected to deliver an estimated 625 horsepower (466 kW) and 635 lb-ft of torque (861 Nm). To balance performance and efficiency, the LT4 leverages the same trio of advanced technologies introduced on the Corvette Stingray: Direct injection, Active Fuel Management, or cylinder deactivation, and continuously variable valve timing. These technologies - combined with the fuel-efficient multi-speed transmissions, aerodynamic design and lightweight construction - help make the new Z06 surprisingly fuel efficient. “The supercharged LT4 engine delivers the greatest balance of performance and efficiency ever in the Corvette,” said John Rydzewski, assistant chief engineer for Small-Block engines. “It is one of the world's only supercharged engines to incorporate cylinder deactivation technology, enabling it to cruise efficiently on the highway with reduced fuel consumption, but offer more than 600 horsepower whenever the driver calls up its tremendous power reserve.” To maintain the Z06's mass and performance targets, the LT4 engine was designed with a more- efficient, more-compact supercharger. Even with its integrated supercharger/intercooler assembly mounted in the valley between the cylinder heads, the engine is only about one inch (25 mm) taller than the Corvette Stingray's LT1 engine - while delivering nearly 37 percent more horsepower and 40 percent more torque. The new 1.7L Eaton R1740 TVS supercharger spins at up to 20,000 rpm - 5,000 rpm more than the supercharger on the Corvette ZR1's LS9. The rotors are shorter in length, too, which contributes to their higher-rpm capability - and enables them to get up to speed quicker, producing power-enhancing boost earlier in the rpm band. That boost is achieved more efficiently, thanks to a new, more direct discharge port that creates less turbulence, reducing heat and speeding airflow into the engine. The LT4 engine also has several unique features designed to support its higher output and the greater cylinder pressures created by forced induction, including: · Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat better than conventional heads · Lightweight titanium intake valves and machined connecting rods for reduced reciprocating mass · High 10.0:1 compression ratio - for a forced-induction engine - enhances performance and efficiency and is enabled by direct injection · Forged aluminum pistons with unique, stronger structure to ensure strength under high cylinder pressures · Stainless steel exhaust headers and an aluminum balancer that are lighter than their LT1 counterparts · Standard dry-sump oiling system with larger cooler capacity than Z51; used with dual-pressure- control oil pump.