Jaws dropped when Chevrolet first announced the 2020 Chevrolet Corvette Stingray coupe would accelerate 0 to 60 mph in less than three seconds with the available Z51 Performance Package. Today, the brand confirms the sportscar with the available Z51 Package can reach 60 mph in 2.9 seconds and cross the quarter mile mark in 11.2 seconds at 121 mph.
Even without the available Z51 Package, a base Stingray, starting at $59,995 (including destination charges, excluding tax, title, license, and dealer fees), can reach 60 mph in three seconds flat and cross the quarter mile mark in 11.2 seconds at 123 mph. Performance numbers may vary, as different climates, tire conditions and road surfaces may affect results.
“The performance of the 2020 Stingray has far exceeded our expectations,” said Alex MacDonald, Chevrolet vehicle performance manager. “Moving more weight over the rear wheels helps us get off the line quicker, but it’s the integration between the powertrain and chassis that really takes the performance to new levels.”
0 – 60 mph (sec)
Quarter-mile accel (sec)
11.2 at 123 mph
2020 Stingray with Z51
11.2 at 121 mph
This groundbreaking performance is achieved through a formula of rear weight bias, tire technology, aerodynamics, chassis tuning and of course, the powertrain. The 6.2L LT2 Small Block V-8 engine and eight-speed dual-clutch transmission are in many ways the stars of the show.
Chevy’s Small Block Hits the Gym
The LT2 is the only naturally aspirated V-8 in the segment and is SAE-certified at 495 horsepower (369 kW) and 470 lb.-ft. (637 Nm) of torque when equipped with performance exhaust, making it the most-powerful entry Corvette ever.
“The LT2 is one of our best efforts yet in Corvette’s history of naturally aspirated high performance Small Block V-8 engines,” said Jordan Lee, GM’s global Chief
Engineer of Small Block engines. “This engine is incredibly powerful and responsive. Power is readily available when the driver needs it.”
The standard engine-mounted dry sump oil system boasts three scavenge pumps, which help make this the most track-capable Stingray in history. The LT2’s lubrication system keeps oil in the dry sump tank and out of the engine’s crankcase. It provides exceptional engine performance even at lateral acceleration levels exceeding 1g in all directions. The low profile oil pan is high- pressure die casted – similar to some of Corvette’s large body structure parts – to reduce mass and is only 3.5 mm thick. The LT2’s pan-mounted oil filter and cooler assembly has cored oil and coolant passages, allowing for a 25 percent increase in cooling capacity over the LT1.
Much of the LT2’s additional power can be attributed to how much better it breathes. The intake system is a low restriction design and incorporates identical 210mm length intake runners and an 87mm throttle body. The performance header exhaust manifolds are also low restriction and feature a stylized four-into- one design with twisted runners to allow for thermal expansion. The camshaft now has 14mm gross lift on the intake and exhaust with an increased duration for both profiles, which helps the combustion system take advantage of the extra flow capacity. The LT2 retains variable valve timing, with 62 crank degrees of cam phasing authority.
The LT2 has a very low-profile oil pan. This allows the engine to be mounted low in the vehicle for a low center of gravity and improves handling and track performance. The DCT’s flywheel dampener was even reduced in diameter to allow for the lower engine position.
Bespoke DCT Puts the Power Down
Chevy’s first eight-speed dual-clutch transmission was designed to do two things – put the LT2’s power down and put a smile on every driver’s face. The bespoke, transaxle transmission was developed with Tremec to provide uninterrupted torque delivery whether setting a new lap record or heading out on a roadtrip.
“The goal from the beginning was to design a transmission worthy of an exotic supercar that is fun to drive everyday,” said Terri Schulke, GM global chief engineer of transmissions. “We achieved that goal by combining the best attributes of the LT2 and the DCT, and I think the impressive performance numbers speak for themselves.”
Engineering decided to use a dual-clutch design because it better supports the Stingray’s new mid-engine architecture and desired performance. The DCT aids vehicle performance with a very low center of gravity, enables desired weight
distribution and offers maximum traction under acceleration. It is a highly integrated system, as it houses the differential, final drive, controls system, sensors, lubrication and cooling hardware.
The heart of the DCT uses dual concentric wet clutches that are opened by springs and closed by hydraulic pressure. The two clutches work in tandem for uninterrupted torque delivery as they toggle between gears. A separate lube circuit is used for on-demand clutch cooling to reduce parasitic losses. Holes in the outer housing allow for the wet clutches to operate moist instead of submerged. Gear ratios were engineered to be incredibly low-end biased for maximum acceleration. First gear takes advantage of the additional traction to get off the line quickly and reach 60 mph in 2.9 seconds with the Z51 Performance Package. The Z51’s 11.2 second quarter-mile acceleration is achieved by lightning-fast upshifts and excellent low-end torque. The gear ratios are:
The final drive and differential are integrated for the first time and make for an incredibly efficient package. A mechanical slip differential is standard on all 2020 Stingrays. The mLSD has an effective final drive ratio of 4.9:1 and is intended for straight line acceleration and dynamic handling. An electronic limited slip differential is offered on the Z51 Performance Package and has an effective final drive ratio of 5.2:1. It is intended for ultimate control during track driving and commands more authority than previous generation eLSDs.
Though they have different purposes, the mLSD and eLSD were engineered together. They share a common ring and pinion gear ratio of 3.55:1. Their ring and pinion gears also use a zero offset spiral bevel as opposed to the typical hypoid arrangement, which allows for a common fluid to be used and benefits overall packaging.
Plays Key Role
Beyond hardware, the transmission software controls are really where customers will find the most tangible benefits. Most of these will feel familiar when toggling through varying driver modes:
- Tour: Moves to the background to provide quiet, smooth shifts for optimal ride comfort.
- Sport: Gives drivers altered up and downshifts for more spirited driving.
- Track: Maximizes vehicle performance with aggressive gear selection expected to keep the engine in a peak performance window.
A proprietary algorithm will influence gear selection if the car senses spirited driving. The level of aggressiveness will change with modes, but when sensed, the DCT can downshift early on hard braking, hold gears when lifting off the throttle and alter shifts points with lateral acceleration. All behaviors are intended to increase driving enjoyment and avoid unnecessary shifting.
To achieve peak acceleration numbers on the Stingray, drivers must initiate a performance launch. Once in Track mode, double pressing the traction control button will put the vehicle in Performance Traction Management for Magnetic Ride Control-equipped cars or Competitive driving mode for all others. Once prepared, the driver can then fully depress the brake and accelerator pedal together, and then release the brake pedal once 3,500 RPM are reached.
Extensive work went into ensuring the DCT felt like the best of both worlds: the spirited, direct connected feeling of a manual and the premium driving comfort of an automatic. The magnesium steering wheel-mounted paddle shifters give a premium feel when pulled. For the most responsive shifts possible, the shift signal is sent directly to the transmission control module the moment the paddle pull begins. This avoids any communications delay through other modules and allows drivers precise control of their gear selection.
Unique features of the ergonomic paddles are:
- Double paddle declutch – pull both paddles simultaneously to simulate pressing a clutch pedal.
- Temporary manual – simply use either paddle while in Drive, and the vehicle will temporarily switch to manual mode.
- Lowest available gear – hold the downshift paddle and the transmission will shift to the lowest available gear for a quick burst of torque.
All in all it does seem like the transition to a dual clutch box was necessary to get the performance out of the C8 Corvette that Chevy was looking for, though that doesn’t offer much solace for losing yet another manual transmission.