C8 Corvette Dual-Clutch Transmission Revisions Promise Improvement
C8 Corvette Dual-Clutch Transmission Revisions Promise Improvement
C8 Corvette reviewers didn’t love the pre-production DCT, but the production versions will be better.
If you read the 2020 Chevrolet Corvette initial drive reviews, you likely know the new dual-clutch transmission was one of the things that reviewers didn’t love. Shifts were not as concise as reviewers expected, sometimes allowing the engine to hit the rev limiter. In other situations, downshifts were denied by the computer system at times when a downshift was logical.
Car and Driver magazine described the new DCT (dual-clutch transmission) as the, “weakest component in the pre-production C8 Stingray” during their Performance Car of the Year testing. The magazine also points out that the “clumsy” transmission was part of why the mid-engine Corvette didn’t take the title. However, C&D is quick to point out that their test subject was a preproduction model and engineers are continuing to fine-tune things like the transmission characteristics.
Fortunately, Chevrolet recently held powertrain engineering seminar, where the outlet had a chance to talk to the man in charge of the dual-clutch transmission program.
Transmission Tuning in Progress
Glen Hoeflinn, program manager for the dual-clutch transmission, addressed the complaints with the new transmission, explaining that the Corvette gearbox is being tweaked.
“Maybe you get some humpy-bumpy shifts here, you get a little bit of that there. That all gets refined out,” Hoeflinn told Car and Driver. “It’s in final refinement, and then it’s in final checks and looking what we’re doing and making sure that it’s behaving exactly [how] we want. That’s what we’ve done since the car that you had. Doing all that refinement and making sure it’s ready to go for everybody across the all the cars.”
Hoeflinn also explained the difficulties of the dual-clutch transmission. Many processes occur in the background in an effort to prepare for the next shift. “It’s the same choreography between the engine and transmission, but without the ‘luxury’ of a torque converter, there’s a lot more programming work involved.”
“As you’d expect, the transmission has different automatic shift strategies for the various drive modes, which adapt in real-time. The more aggressive, the more spirited you drive, the more aggressive the car’s going to respond,” Hoeflinn said. “As you start to relax, the car’s going to start to relax.”
C8 Corvette Transmission Tricks
The Car and Driver piece also discussed this gearbox’s advantages. For example, the transmission uses accelerometers, throttle position, and steering angle to decide how hard to shift or when to shift. In Track Mode, the transmission downshifts more aggressively if it feels the car diving into a turn. It also holds the gear longer.
The C8 Corvette also has two forms of manual shift mode. Engage one by pulling back on either of the shift paddles. This mode can “time out” and return to an automatic shift program. The driver can also hold down the upshift paddle to leave manual mode. Engage the other manual mode with the “M” button on the center console. This locks the transmission into a manual mode, where it will not time out and upshift on its own.
Next, as the driver of the new Corvette approaches a turn at speed, he or she can hold the downshift paddle to request the lowest “safe” gear. Or you can hold the paddle down to downshift continuously. Or pull both paddles to decouple the transmission and rev the engine while sitting still.
The Car and Driver piece goes into serious detail on the components and function of the dual-clutch transmission. Rather than repeat all of that, we suggest that you click here to read the fuel article.
Photos: Chevrolet
