Chevrolet has announced that The King of the Hill returns with the most powerful V8 ever produced in America to challenge the world’s best supercars.
“The team that revolutionized Corvette with a mid-engine architecture took on another challenge: take ZR1 to the next level,” said Scott Bell, vice president, Chevrolet. “Corvette ZR1 is about pushing the envelope with raw power and cutting-edge innovation. From Stingray, to Z06, E-Ray, and now ZR1, the Corvette family continues to elevate with each new iteration — and challenge the best in the world.”
ZR1’s 5.5L LT7 twin-turbocharged DOHC V8 engine features the same architecture as Z06’s LT6 and adds twin turbochargers. Dubbed the “Gemini V8”, the LT6 program was only the beginning as engineers dual-pathed a goal: to create massive power, capability and character from naturally aspirated and turbocharged flat plane crankshaft twin engines.
Unique to the 5.5L LT7 twin-turbo V8:
- Head castings with unique ports and a larger combustion chamber
- Valve train timing and lift profile optimized for forced induction with higher exhaust temp enabling exhaust valves
- Completely new intake system tuned for twin turbochargers
- CNC machined combustion chamber, exhaust and intake ports specific to the LT7
- Dual, ported shroud, ball bearing, mono-scroll (76 mm) turbochargers integrated with the exhaust manifold to reduce the volume and distance from the exhaust valve to the turbine wheel for quick response with electronic wastegates
- Intelligent anti-lag engine calibration techniques specifically for ZR1 that adapt and react to driving style
The LT7 engine also builds upon this engine architecture with:
- Added block and head machining to support turbo cooling and oiling
- Counterweight changes to account for a unique piston, and unique connecting rod for the crank train
- A secondary port fuel injection system added to deliver the needed additional fuel to support the engine’s massive output
To support the dramatic increase in power from the LT7 engine, engineers made numerous changes to the Corvette ZR1’s eight-speed dual-clutch transmission, including:
- Inner and outer input shaft upgrades
- Increased gear capacity with strength increased via shot peening for all gears
- Final drive refinements
- Oil management to support increased vehicle longitudinal and lateral capability
- Increased control valves to accommodate the higher required clutch clamp load for LT7
The LT7 engine is purpose-built to accomplish its four-figure horsepower mission with no compromises and maintains the rev-happy character that is the heart of the Gemini V8 engine family. It will be hand-assembled by the master engine builders at the Performance Build Center, part of the Bowling Green Assembly Plant in Kentucky. Production will begin in 2025.
Specific aerodynamic and cooling changes found throughout the car include:
- Flow-through hood: Air enters the front grille, flows through the intercooler heat exchanger and exits the hood to increase front downforce and cool charged air temperatures.
- Carbon fiber side profile air ducts: Clean, cool air is funneled through ducts, which are cleanly integrated into the signature wishbone bezel behind the cabin doors to cool the rear brakes through an intricately designed system that doesn’t impact rear wheel travel
- Unique fresh air intake ducts: Carbon fiber inlets located on top of the coupe rear hatch ingest air to cool the turbo compressor inlet air temperatures
“We went into the ZR1 program with lofty goals, but even our first development tests on-track showed the teams were already exceeding them,” said Tadge Juechter, executive chief engineer, Corvette. “As we worked to develop this car, we continued to leap past expectations, and we knew we had a special Corvette on our hands.”
The Corvette ZR1’s cockpit dials up the attention to detail, notably with unique ZR1 badging found on an interior plaque, the sill plates and steering wheel. A new finishing stitch pattern for the doors, specific to ZR1, is available on the 3LZ trim. A boost gauge is also present, denoting the first factory turbocharged Corvette in the nameplate’s history.
Providing further choice to customers, the Corvette ZR1 will provide a roster of customization between exterior and interior colors. Shared with the 2025 Corvette lineup, new colors such as Competition Yellow, Hysteria Purple and Sebring Orange headline updates. The latter recalls a fan-favorite hue from the previous C7-generation Corvette ZR1.