How the Mid-Engine Corvette C8 Could Still Get a Stick Shift
The most controversial aspect of the just-revealed mid-engine C8 2020 Chevrolet Corvette is, without question, the lack of a manual transmission. A recent GM patent for an electronic clutch pedal, combined with manual shifter technology from the C7 Corvette, though, could be combined to create a futuristic electronically controlled manual shifter for the C8.
Yes, you read correctly that the C8 has only one transmission option as of now: a new eight-speed dual clutch automatic co-developed with transmission specialist Tremec. You also read correctly that Chevrolet currently has no plans for a torque-converter automatic or a manual transmission. Thanks to modern technology, it’s possible for both of those things to be true and for the C8 to get a stick shift.
How? A manual transmission shifter that tells the transmission which gear to select and an electronic clutch pedal, both of which GM has in its engineering arsenal.
Chevrolet, probably without intending to, gets us pointed in the right direction. In the official press release, Chevy writes “with this electric shifter there’s no mechanical interface between the shift lever and the transmission.” This matters because shifter cables would need to get from the cabin to the transmission behind the engine, and there’s an engine and a dry sump oiling system in the way (It’s also interesting Chevrolet chose to use the term “shift lever” when describing a push-button electronic shifter).
Now, think back to the C7 Corvette launch in 2013. Chevrolet engineers at the time boasted of adding a Hall effect sensor to the manual shifter which would sense which gear you were shifting to. At the time, this was used to inform the automatic engine rev-matching software. This is important, because it means Chevrolet already has a manual shifter that can tell a computer exactly what gear you want to put the transmission in without any mechanical connection to the transmission. It’s the same thing paddle shifters are already doing, just with a stick instead.
The other big engineering puzzle is the clutch pedal, and patent sleuth Bozi Tatarevic sniffed out the solution 10 months ago. In a patent filing published on September 6, 2018, GM describes an “Electric Slave Cylinder for Manually Shifted Vehicles.” Ignore the slave cylinder and the patent drawings (which look suspiciously like they used a 25 year old Getrag 282 front-wheel drive manual transmission as a starting point) and skip to the part about the clutch pedal sensor. The electric slave cylinder gets its instructions on opening and closing the clutch from a sensor on the clutch pedal. Chevrolet suggests in its description this electronic clutch pedal would incorporate artificial feedback in order to maintain the “feel” of the clutch pedal even when the clutch itself is getting old and worn-out. This kind of force feedback technology already exists for brake-by-wire systems and could be adapted to make an electronic clutch pedal “feel” like a mechanical one.
What of the transmission itself? It’s the exact same eight-speed dual-clutch already designed, engineered, crash-tested, and EPA certified. With an electronic clutch pedal and an electronically monitored shifter, all that’s needed is a few million lines of software code telling the transmission what to do when the driver presses the clutch and moves the lever. No doubt it would be a long, arduous process programming the transmission’s clutches to behave like a manual and get the feel and response of the electronic clutch pedal right, but nothing about it is technically infeasible. Corvette engineers have already spent countless hours programming the dual-clutch transmission to make it feel the way they want, so they’re certainly familiar with the process.
Thus, a clever engineering team can build a virtual manual transmission that’s entirely electronically controlled using off-the-shelf parts and a lot of programming. With existing technology and parts, Chevrolet could offer the experience of old-school manual shifting in the high-tech C8 Corvette at a far lower cost than developing, testing, and certifying a second transmission that would only fit one relatively low-volume product.
Never mind that dual-clutch automatic transmissions are universally accepted as superior for quicker lap times, manual transmissions have a special place in the hearts of car enthusiasts. Whether it’s intimate control of the vehicle or nostalgia or just personal preference, demand for manuals still exists among the Corvette’s target audience, and this combination of technologies could help Chevrolet satisfy the purists with reduced cost and clever engineering.
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