Photo: GM
GM has finally done the right thing, with the company now offering the the eight-speed automatic introduced on the 2015 Corvette Z06 on the standard 2015 Corvette Stingray.
The C7 Corvette, especially with the Z51 package, feels like quite a collection of technical assets, but its aged six-speed auto was obviously a weak link. Like we said, the C7 now receives the 8L90 transmission as an option.
The torque converter, as well as the five-clutch pack, have been adapted for the C7’s lower torque, but most of the hardware is shared with the supercharged Z06. Moreover, the eight-speed auto is eight lbs (four kilograms) lighter than the six-speed slushbox.
GM explains that the new tranny brings a five percent efficiency boost, thanks to the extra gears and the lowered internal friction. The EPA figures are still pending though.
More importantly, GM brags the gearbox, an in-house development, can perform full-throttle upshifts "up to eight-hundredths of a second quicker than those of the dual-clutch transmission offered in the Porsche 911.” Paddle shifters, rejoice!
Apparently, the magic lies in a smart hydraulic pump, which works a bit like the Corvette’s cylinder deactivation system. The pump comes with dual ports, whic hare used during rushed shifts. As for the normal operation, the transmission relies on a single port for this, reducing friction and allowing for a smoother operation.
If the gearset is identical to that in the Z06, then we’ll have the sixth ratio being used as the direct drive, with seventh and eight offering overdrive ratios os 0.86 and 0.65, respectively.
Well, at least now we have something to counterbalance the 2015 Corvette pricing increase.
The torque converter, as well as the five-clutch pack, have been adapted for the C7’s lower torque, but most of the hardware is shared with the supercharged Z06. Moreover, the eight-speed auto is eight lbs (four kilograms) lighter than the six-speed slushbox.
GM explains that the new tranny brings a five percent efficiency boost, thanks to the extra gears and the lowered internal friction. The EPA figures are still pending though.
More importantly, GM brags the gearbox, an in-house development, can perform full-throttle upshifts "up to eight-hundredths of a second quicker than those of the dual-clutch transmission offered in the Porsche 911.” Paddle shifters, rejoice!
Apparently, the magic lies in a smart hydraulic pump, which works a bit like the Corvette’s cylinder deactivation system. The pump comes with dual ports, whic hare used during rushed shifts. As for the normal operation, the transmission relies on a single port for this, reducing friction and allowing for a smoother operation.
If the gearset is identical to that in the Z06, then we’ll have the sixth ratio being used as the direct drive, with seventh and eight offering overdrive ratios os 0.86 and 0.65, respectively.
Well, at least now we have something to counterbalance the 2015 Corvette pricing increase.
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