Years in the making, the original C8 Corvette DCT design forced the development team to change course in a big way.
The C8 Corvette marked a monumental shift in the sports car’s history when it debuted in 2019 for the 2020 model year, for a number of reasons. The biggest, of course, is the fact that the latest version of the Corvette has switched to a mid-engine layout, a change that’s been decades in the making and obviously required a good bit of engineering to pull off. However, this switch also meant that GM needed a suitable gearbox – particularly since it also chose to ditch the manual altogether. The team went on to develop a rear-mounted, dual-clutch gearbox, but the original plan for the C8 Corvette DCT was a bit more complicated than what ultimately came to be, as Tadge Juechter recently explained to Design News.
These decisions were a big deal because at the time – around 2006 – dual-clutch transmissions weren’t terribly common just yet, outside of Porsche’s PDK. Developing the C8 Corvette DCT would also prove to be a costly and time-consuming venture, as well as a risky one. “We had moved the transmission to the back, but it’s essentially a front transmission and we just adapted it to move to the rear to enable our architecture but it was a high-volume transmission shared with lots of other products in GM,” Juechter said. “We don’t have a transmission with a differential ahead of the speed gears. So it’s a completely different architecture. And at that time, in 2006-2007 DCTs weren’t as prevalent as they are today.”
The Corvette team originally planned to develop a seven-speed unit rather than the eight-speed gearbox that’s present in the C8, and it knew that preventing noise, vibration, and harshness was going to be a challenge since they were going to run active fuel management in the car. The team aimed to absorb the torque “bumps” caused by AFM using friction clutches at first. “We know a torque converter works,” Juechter said of their thinking at the time. “It’s essentially a manual transmission behind it. Let’s put a torque converter ahead of it. Our plan was engine-into-torque-converter, torque-converter-into-clutches, and clutches-into-the-gears. So it ended up being this rather massive construction.”
After teaming up with Tremec to bring the C8 Corvette DCT to life, the longtime transmission maker purchased a company in Europe called Hoerbiger, which was already designing control systems for dual-clutch transmissions in that part of the world. Ultimately, the final design of the Corvette’s gearbox is far simpler than the team originally planned, but it took a pretty substantial team effort, years of development, and an expanding market for that to happen.
Photos: Chevrolet
Keyword: C8 Corvette DCT Was Originally Going to Utilize a Torque Converter and a Clutch