Who doesn’t love the feel of the shift? The power that comes with pressing the clutch, manually engaging the gears, and revving the RPM at will, is still part of the thrill.
Lately, much has been said about the fuel economy and improved performance of automatic transmission-equipped Corvettes. Automatic transmissions nowadays are undoubtedly a monstrosity of integrated engineering and technology.
In addition to highly computerized automatic transmissions, more and more manufacturers, such as Audi, Honda, Nissan, Ford, and GM are experimenting to integrate CVTs into their drivetrains.
So, we couldn’t help but wonder, what if a Corvette was equipped with a CVT? Or better yet, what could a CVT do for Corvette?
A little review…
As we know, the function of a transmission is to change the speed ratio between the engine and the wheels.
Imagine driving a car with only one gear. If a car only had first gear, it would be easy to take off, but it would not be possible to travel at high speeds. Now imagine trying to take off from a stop light in fourth gear. Get the picture?
A transmission, manual or automatic, uses gears – from low to high and high to low – to transfer the engine’s power ratio to the wheels allowing the vehicle to achieve all desired speeds while maintaining correct engine RPM.
What is a CVT?
Believe it or not, the CVT, which stands for “Continuously Variable Transmission,” was conceived by Leonardo Da Vinci more than 500 years ago. Unlike the type of transmission (automatic or manual) that we are accustomed to, the CVT transmission does not shift as we know it.
An elegant design indeed, instead of using gears to create the different driving ratios, the CVT is driven by a heavy-duty chain riding on a ribbed pulley system. Hydraulic actuators allow the range of ratios to be varied infinitely between the highest and lowest gears with no shifts. The operation is invisible to the driver, and you will find yourself driving a “shiftless” vehicle.
There are three different types of CVTs: Pulley-Based, Toroidal, and Hydrostatic. Instead of a complicated array of gears, clutches, and governing devices, the pulley-based CVT uses only three basic components: a heavy-duty metal belt, a variable input driving pulley, and an output-driven pulley.
The simplicity of the pulley-based CVT makes it an ideal transmission, but CVTs have also experienced their fair share of pros and cons.
In previous applications, CVTs relied on high-density rubber belts that stretched and slipped, thus reducing efficiency and durability.
New materials, however, have made CVTs more reliable and efficient. One of the most significant developments was the design of metal belts to connect the pulleys.
The flexible metal belts are made of thin bands of steel that hold together bow-tie shaped metal links. Metal belts do not slip, are highly durable, can handle more torque, and are quieter than rubber belts.
The Corvette 8L90 8-Speed Transmission
As we featured in our article “First Look: 2015 Corvette 8-Speed Automatic and Supercharged LT4 V8,” an 8-speed transmission may have sounded like a bit too much, but first gear in the 8L90 is a 4.56 ratio as opposed to a 4.03. The closer steps between ratios result in improved performance and better fuel economy.
Chevrolet claims 29 mpg highway and 0-60 in 3.7 seconds. The 8L90 features a 7.0 ratio stretch between first and eighth gear, managed by an external controller with incredible processing speed.
The impressive 8-speed fits in the same space as the previous 6-speed, weighs eight pounds less, and can handle up to 650 lb-ft. torque.
If the purpose is to improve performance and fuel economy with closer step ratios, then, what if those ratios are infinitely varied without steps. That is yet to be seen coupled with a supercharged 6.2L V8 engine.
How much are those variable ratios willing to output? And, how much more torque is a CVT capable of handling? As it stands, it is no longer a question of whether a Corvette can have a CVT, but whether a CVT can handle a Corvette.
At the time of press, we have not heard of GM planning to build a Corvette with a CVT drivetrain. According to Greencarreports.com, GM’s new CVT is likely to appear in some “high-volume” models by 2019.
But, what if Corvette was to appear on the list of vehicles phased for a CVT? How would you feel about it? Are you still a die-hard, knuckle-busting stick shift ‘Vette driver, or can you see yourself as a cool and “chill” shiftless cruiser in a CVT Corvette?