Since the 1940s, automatic transmissions have spouted generations of motorists who are not troubled by the chore of manual shifting. Saving some from what could be uncomfortable drives, a passionate group of manual transmission lovers who cannot accept true driving without a lever action to actuate the gear selection. To sports car fans, automatic transmissions are a loathed piece of equipment on an otherwise driver-centric vehicle.
In the 60 years of the Chevrolet Corvette, an automatic transmission has been part of all seven generations including the very first year in 1953. The 1953 Corvette combined a two-speed Powerguide automatic gearbox with the “Blue Flame” inline-six engine for what was rather ho-hum performance. It wasn‘t until 1955 when a manual transmission was made available on the Chevrolet Corvette. Since 1955, the optimum presence of the sports car was with the manual gearbox. On the 2014 Chevrolet Corvette Stingray, seven gears are included on the manual shifting transmission choice. The base Corvette Stingray has been delivering a six-speed automatic transmission with paddle shifters to drivers more invested in cruising than matting the full performance of the sports car. An acceptable transmission for the 2014 model year vehicle, Chevrolet has announced the extension of a new automatic touring two new gears.
An eight-speed automatic transmission will be offered on 2015 model year Chevrolet Corvette Stingrays. The 8L90 eight-speed automatic will boast five-percent greater efficiency than the six-speed it is replacing. Despite the increase in gears, aluminum and magnesium used in the construction of the 8L90 automatic transmission allows it to weigh eight pounds less than its predecessor. The same 8L90 automatic gearbox mentioned on the new 625-horsepower Corvette Z06, the transmission has been modified specifically to the 6.2-liter LT1 V-8 engine. In adapting the eight-speed automatic from the supercharged Corvette Z06 powerplant to the naturally aspirated Corvette Stingray, a clutch and torque converter have been matched to the performance characteristics of the base 2015 sports car.
While fully automatic, engineers behind the new eight-speed transmission for the 2015 Chevrolet Corvette Stingray has stated the new gearbox is designed to mirror performance of the highly sophisticated dual-clutch layouts employed by the Audi R8 and the Porsche 911. Assistant chief engineer Bill Goodrich commented on the new unit saying, “Corvette 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,”. With a controller computing and prepared to adjust the parameters of the automatic transmission 160 times per second, upshifts are said to be up to 8/100ths of a second faster than the Porsche 911 with its dual-clutch gearbox. The fully automatic 8L90 eight-speed transmission will exhibit smoothness greater than what is found with dual-clutch equipped supercars. Like the six-speed transmission, the new eight-speed automatic will offer the driver manual-shifting properties through shift paddles behind the steering wheel.
Performance figures and EPA certified fuel economy numbers for the 2015 model year Chevrolet Corvette Stingray with the more efficient eight-speed automatic transmission has yet to be confirmed. The exploration for increasing gears for automatic transmissions beyond eight speeds is already underway for automakers. A nine-speed automatic has recently been introduced to the marketplace on the Range Rover Evoque as well as by Chrysler presently available with the Jeep Cherokee. In the case of General Motors, the car company announced a technical partnership with Ford to jointly develop a nine-speed as well as a ten-speed automatic transmission.
Information and photo source: General Motors