An eight speed automatic transmission has been made available for the 2015 Chevrolet Corvette Stingray, replacing the current six speed offered at present. Rumours have been that the General Motors (GM) 8L90 gearbox first announced for the Corvette Z06 might not make it to the standard C7 until 2016.
This addition will make the Corvette Stingray one of the few sports cars to offer the choice of a conventional manual transmission or an eight speed automatic.
The 8L90 is built at GM's Toledo, Ohio, transmission facility. The eight speed automatic with a torque converter has been retuned for the lighter torque load of the C7 but it's built on the same foundation as the equipment that goes into the Z06. GM states that the expanded gear-set and reduced friction internals make for a 5% improvement in efficiency, but EPA mileage numbers aren't ready yet.
For performance driving, the transmission offers full manual control through steering wheel paddles. A new transmission-control system and unique algorithms deliver shift performance that rivals the dual-clutch/semi-automatic transmissions found in many supercars, but with the smoothness and refinement that comes with a conventional automatic fitted with a torque converter.
The company also says that, “the transmission controller analyses and executes commands 160 times per second. Wide-open throttle upshifts are executed up to eight-hundredths of a second quicker than those of the dual-clutch transmission offered in the Porsche 911.”
With four gearsets and five clutches, creative packaging enables the new eight-speed automatic to fit the same space as the previous six speed automatic. Extensive use of aluminium and magnesium make it more than eight pounds, or 4 kg, lighter than the six speed.
Assistant Chief Engineer for the eight speed auto, Bill Goodrich, commented, “Corvetts Stingray's new eight-speed automatic delivers the comfort and drivability of a true automatic transmission, as well as lightning-fast shifts and the manual control that enhance the performance-driving experience. It was designed to enhance the Stingray's driving experience, with performance on par with dual-clutch designs, but without sacrificing refinement.”
The 2014 Chevrolet Stingray coupe starts at $51,995 and the Corvette Stingray Convertible starts at $56,995.