The official performance figures for the 2020 Corvette Stingray may have leaked out via an official General Motors document that is making its way around enthusiast forums.
Leaked may be the wrong term to use here, as GM has of course already debuted the 2020 Corvette Stingray in its entirety. Corvette chief engineer Tadge Juechter was quoted in saying the team still had some tuning and validation testing to complete on the car, however, which is likely why GM has only released a limited amount of performance figures thus far. Nevertheless, let’s see what this alleged “leaked” document reveals about GM’s new mid-engine sports car.
According to the document, the 2020 Corvette Stingray base model will accelerate from 0-60 mph in 3.0s flat and accelerate from 0-100 mph in 7.6s. It also indicates it will be able to complete the quarter-mile in 11.3s at 121 mph and top out at 193 mph (oddly, a GM press release said the top speed was 194 mph). The performance figures for Z51 performance package equipped models are identical, however the 0-60 mph time drops by 0.1s to 2.9s.
Here’s some of the best bits from the document:
- Curb Weight Base Coupe: 3,535 lbs
- Curb Weight Z51 Coupe: 3,577 lbs
- Curb Weight Convertible: 3,637
- Engine Weight: 466 lbs
- Transmission Weight: 341 lbs
- Weight Distribution F/R: 40/60
- Drag Coefficient: 0.32
- 0-30 mph: 1.1s
- 0-60 mph (Base, Z51): 2.9s, 3.0s
- 0-100 mph: 7.6s
- Top Speed: 193 mph
- Quarter Mile: 11.3s @ 121 mph
- Braking 60-0 (Base/Z51): 115.2 feet, 108.4 feet
- Power-to-Weight Ratio: 7.22 lbs per horsepower (base model)
We will reiterate that these figures have not been confirmed by GM in any way, so take what you see here with a grain of salt. They are in line with what we’ve reported previously, however, and nothing here seems unrealistic.
It’s interesting to see the weight of the convertible, which appears to be just 102 lbs heavier than the coupe. The rigid structures of modern-day mid-engine cars mean very little additional chassis bracing needs to be used when engineering convertible model variants, if any at all.
It will also be interesting to see how close to the claimed 0-60 times media will be able to get. Magazines that conduct internal instrumented testing sometimes find it hard to consistently achieve the manufacturer’s claimed 0-60 times, but such performance metrics are dependent on a variety of factors including weather, surface condition and the driver.
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Source: MidEngineCorvetteForum.com
Comments
Need to figure out the idea of Drag Coefficient, i still do not understand it well. Tesla have .23 where Corvette has .32.
Some one please help me to understand this term better .
The drag coefficient is the drag divided by the cross sectional area (the area of the silhouette when seen from the front) of the vehicle. Since the Corvette is a much lower vehicle than a mid sized sedan like a Tesla it can have less drag but a larger drag coefficient.
Additionally the Tesla is primarily designed for low drag, whereas the Corvette is designed to generate downforce as well. Downforce always has a drag penalty.
To be a bit more specific, drag coefficient is drag force divided by the product of dynamic pressure times projected frontal area: CD = D/(q*A). Or, turning it around, D = CD*q*A. Dynamic pressure is a function of velocity squared and air density (rho, which depends on temperature, barometric pressure, and humidity): q = 1/2 * rho * V^2. This is why drag increases with the square of velocity. Projected frontal area is a stack-up of all cross sections, or (as C7 Dave said) the area of the silhouette when seen from the front.
I believe this is done by taking the car up to a certain speed, trans kicked into neutral and the time how long it take the car to reach a certain speed as it slows down determines the C of D. How do you calculate the drag coefficient on a car?
If you take away the force produced by the engine (by putting the car in neutral, for instance) then the only force on the car is the drag. Since there is a net force on the car, the car will begin to decelerate. If you can measure the mass of the car and the acceleration, then you can determine the force.
CD can be derived from coastdown tests, but it’s very difficult to control all of the variables such as ambient winds, temperature, road surface and grade, changes in ride height, etc. Aerodynamic drag is not the only force on the car. There are also tire rolling resistance, brake drag, bearing drag, and related driveline losses between the wheels and the rotating parts of the transmission when in neutral. All of those are dependent on the temperature of each component, which changes constantly. So it becomes extremely challenging to separate aero drag from all of the other forces. This is why manufacturers invest so much in wind tunnels that provide very repeatable, controlled test conditions, and where drag can be measured independently. On the other hand, wind tunnels are simulators, and some are more accurate simulations than others. Data adjustments are required for correlation to the real world. The simulation accuracy and adjustments produce lower numbers at some wind tunnels than others.
Lower the drag number the more efficent it is. But you also have to consider what it is in too.
The Tesla needs slick shape to add to range and it has no down force what so ever.
In the case of the Corvette it has down force built in. The real spoiler in the center along has 400 pounds of down force. The Corvette is built for lap times not just electric range hence different needs and different drag counts.
Drag is calculated in the wind tunnel. GM has one of the most advance wind tunnels in the world and they can use it for a number of things including drag count.
Aerodynamics is based on two concepts:
Downforce: is to design the car so that the air hits the car to the ground as hard as possible; so that the car is stable at high speeds and cornering, for this there are spoilers; the skirts …..
The other concept is the drag coefficient: it is the air resistance generated by the car when trying to cross the air barrier; the faster the car goes; the air becomes hotter and denser and difficult to pass through and this requires a lot of power.
And the perfect thing is to get a balance between Downforce and drag; more downforce possible; and the least possible drag.
If Corvette achieves what the numbers say; it’s an absolutely amazing job by General Motors
drag doesn’t go up because the air is getting hotter and more dense. it goes up exponentially because drag force is proportional to velocity squared.
Doing a Google search, the C8 differs little over the C7 Corvette it will replace as one has to think the key to the C8’s success in acceleration is location of the engine as it practically sits right over the rear wheels which means there’s no wheel hop as this was a big issue with the C7 Corvette as car testers were never able to get a clean off the line acceleration and it’s why zero-to-sixty time differs so little from the base C7 Corvette Stingray to the ZR1 despite nearly twice the horsepower, one also has to think that the C8 Corvette with 800+ hp as planned in the upcoming Z06 variant of the C8 will make it a true roar rocket.
The Corvette had a drag coefficient: 0.28 since 2004 at least. a Drag coefficient of .32 is, if i recall correctly, 1982 Tans Am level though the’ 83 Vette was .33. The big butt that houses everything isn’t tapered like in the past, and downforce is being prioritized over fuel economy now. Its a numbers game after all, and marketing the 0-60 times is the goal!
Good comparison to the 1982 TransAm, which was outstanding for its time, although that was almost four decades ago. At first glance that’s not very complimentary to the C8, but you need to consider that downforce, cooling airflow, wider tires, packaging requirements of a mid-engine car, and stricter safety requirements all carry a drag penalty. Overcoming all of those is quite an accomplishment by the C8 aero team.
The target is low lap times with good fuel economy, not just 0-60 times.
Once you get below .30 you begin to hit compromises in styling and performance. You end up with a car will a blank nose like Tesla.
As for performance tires are a major part of drag. While this car has large scoops the similar drag to 88 TA does not take into account the much larger tires. The body on the C8 has a lot of Tunnel time and is much more efficient than you would think.
The old cars had smaller tires, and less intricate bodies yet this car matches their numbers.
Trap speed gives the best clue of power. 495hp would be 119.0mph. 121mph means 520hp. Tire, transmission, aero … Don’t affect trap speed much.