The GM twin-turbocharged 5.5L V8 LT7 gasoline engine is the Detroit-based automaker’s most powerful production-spec powerplant ever manufactured, and was unveiled alongside the 2025 Corvette ZR1.
Overview
Debuting as the centerpiece of the Corvette C8 ZR1, the twin-turbocharged 5.5L V8 LT7 gasoline engine is based on the naturally aspirated 5.5L V8 LT6 gasoline engine found in the Corvette C8 Z06. In fact, the two powerplants were developed in tandem with one another. However, General Motors engineers claimed that the 5.5L LT7 was not just an “LT6 build for boost”, but rather optimized for a boosted application.
It’s worth noting that despite widespread expectations for a transition to a cross-plane crank, the 5.5L LT7 retained the 5.5L LT6’s signature flat-plane crank.
As the first production-spec turbocharged engine ever fit into a Chevrolet Corvette, the 5.5L LT7 carried many firsts and featured a laundry list of upgrades to handle its lofty output figures, including:
- Additional block and head machining
- Counterweight changes
- Secondary port fuel injection system
- Head castings with unique ports and a larger combustion chamber
- Valvetrain timing and lift profile optimization
- All-new intake system
- CNC-machined combustion chamber, exhaust and intake ports
- Dual, ported shroud, ball bearing, mono-scroll 76-mm turbochargers
- Anti-lag calibration techniques
Vehicle Applications
Model Year(s) | Application | Transmission | Horsepower @ RPM | Torque @ RPM | |
---|---|---|---|---|---|
2025 – Present | Corvette ZR1 | Eight-Speed Dual Clutch Auto | 1064 @ 7000 | 828 @ 6000 | |
- | Corvette Zora | - | - | - |
Specifications
Type | 5.5L V8 |
GM RPO Code | LT7 |
Displacement | 5.5L |
Compression Ratio | 9.8:1 |
Valvetrain | Dual-Overhead Camshafts, Four-Valves Per Cylinder, Flat-Plane Crank |
Valves Per Cylinder | Four |
Block Material | Sand-Cast Aluminum |
Cylinder Head Material | Aluminum |
Firing Order | 1-4-3-8-7-6-5-2 |
Bore x Stroke (in. / mm) | 4.104 / 104.25 x 3.1 / 80 |
Aspiration | Twin-Turbocharged |
Fuel Delivery | PDI (Direct And Port Injection) |
Ignition System | Direct Coil-on-Plug |
Discussion
Discuss the GM twin-turbocharged 5.5L V8 LT7 gasoline engine in our GM forums.
News
Follow GM Authority’s coverage of GM 5.5L LT7 engine news.
LT7 News
2025 Chevy Corvette ZR1 Hits 233 MPH Top Speed: Video
The C8 ZR1 is the fastest American production car of all time.
Read More »2025 Corvette ZR1 Equipped With Largest Passenger Car Twin Turbochargers On The Market: Video
Boosting the most-powerful production Corvette ever made.
Read More »