2020 Chevy Corvette Z51's Top Speed Is 184 MPH
Chevrolet has confirmed that the 2020 Corvette Stingray with the track-capable Z51 Performance package will reach a top speed of 184 mph, down from the 194 mph officially recorded by the base C8.
The Z51 package adds a front splitter and rear deck spoiler that Chevrolet claims add a total of 400 pounds of aerodynamic downforce compared with the base Stingray.
The increased downforce presses the tires into the pavement and improves high-speed cornering traction but results in greater aerodynamic drag, which makes it harder to push the C8 through the air.
The all-new, mid-engine C8 Stingray's top speed drops from a spectacular 194 mph for the base car to a still impressive 184 mph when the car is fitted with the optional Z51 Performance package, according to Chevrolet. The Z51 package includes a host of upgraded mechanical and aerodynamic components, the latter including a front splitter and a rear spoiler.
Chevy reports that those two pieces together increase the aerodynamic downforce acting on the front and rear of the car by a total of 400 pounds compared with the base Corvette Stingray. Chevrolet hasn't revealed how the additional downforce is divided between the two ends of the car.
In almost all cases, fitting a rear-deck spoiler to create more downforce has the side effect of adding more drag; low-mounted front splitters add little to none. Drag is the force you feel pushing your hand backward when you stick it out the side window of a car that's moving down the road.
The faster you go, the harder it is to hold your palm at right angles to the wind until, at triple-digit speeds, it becomes almost impossible. That's because drag increases with the square of speed. The power required to overcome that drag actually increases with the cube of speed. Say an imaginary car needs 15 horsepower to push it through the air at 50 mph. It doesn't take twice the horsepower (30 hp) to move it at 100 mph—it requires 120 horsepower.
The power required as you go ever faster continues to increase exponentially. The base C8's 490-hp V-8 fights the air to a standoff at 194 mph. Adding an angled blade to the rear deck is like sticking a dozen hands out the window; imagine the force working against them at that speed. That's enough extra drag to slow the Corvette Z51 by 10 mph. It would require a significant boost in power, probably on the order of 75 hp, to bring a Z51's top speed back up to the base car's. Alas, the Z51's dual-mode exhaust adds but 5 hp.
The payoff for adding downforce comes at speeds beyond 50 mph. Put both a base and a Z51 C8 on a fast, winding road or high-speed racetrack, and the aerodynamic aids will stick the car more securely to high-speed turns, enabling it to corner both faster and more confidently. That's exactly what you want for a car fit for track-day flogging and twisty-road explorations. Those extra 10 mph? They'll probably never be missed.
Source: Car and Driver