19th Century Tech Helped Chevy Develop the Most Powerful V8 Aspirated Engine for the Z06

There’s a huge hype surrounding the C8 generation of Chevy Corvette, especially as GM is having a hard time keeping up with the huge demand. The most powerful version of the sportscar will start deliveries in May, as part of the 2023 model year, and this is a highly anticipated moment. The Corvette Z06 makes good use of its LT6 engine, a wonderful piece of technology that combines 21st-century engineering with 19th-century physics discovery to become the most powerful naturally aspirated V8 engine in a production vehicle.

According to the Society of Automotive Engineers (SAE), the most interesting piece of engineering in the LT6 engine is its top hat that fills the V8 lungs with the air needed to produce all that 670 horsepower. The topper is an active induction system, although it does not feature an external boosting device such as a turbocharger or supercharger.

Instead, it relies on a phenomenon discovered in the 19th century by German physicist Hermann von Helmholtz. More specifically, Helmholtz discovered that the air vibrating inside a closed chamber at a pressure slightly above atmospheric produces sounds similar to guitars and whistles. Today this is called the Helmholtz resonance and it's responsible for the positive intake manifold pressure that props LT6’s torque over a broad rpm range.

If you look at the LT6 engine you notice the two black chambers on top that make the engine’s induction system, each of them having precisely 5.5-liters. These ribbed chambers (called plenums in physics) are joined along their lengths by three “communicator” valves that are actuated by the engine’s management system.

Two of them open and close in tandem, but the third has different timing. The mass of air causes pressure waves to reverberate throughout the induction system every time an intake valve closes at the beginning of the compression stroke.

This is adjusted with the throttle position and engine response. At wide-open throttle, the communicator valves remain closed until the engine reaches 2000 rpm, at which moment the paired set opens to foster resonance between the two plenums. As rpm and airflow surge, the third valve opens at 5800 rpm. The induction resonance helps the pressure within the plenums rise to overfill the cylinders with air.

This clever engineering helps the LT6’s with its nearly flat torque curve up to the 6300 rpm torque peak of 460 lb-ft (624 Nm). The power peaks further along, at 8400 rpm, with the 670-horsepower figure helped by the engine’s exceptional efficiency. According to SAE, the volumetric efficiency – a measure of how well the air flows through the engine – is an impressive 110%.

The LT6 engine in the Corvette Z06 uses other engineering tricks to become the most powerful naturally aspirated V8 engine in a production vehicle. For instance, it features a flat-plane crankshaft that, among other things, gives the Z06 a powerful supercar sound. It also uses dry-sump lubrication to help stay lubricated through those high-G turns on the track.

The Corvette Z06 has the most powerful V8 naturally aspirated engine in the world right now, but until it came to reality there was another great engine holding the title. The 6.2-liter V8 M159 engine under the hood of the Mercedes-Benz SLS AMG Black Series coupe developed a total of 622 horsepower (100.3 HP/liter). Thanks to the Chevrolet LT6 engine performance, the AMG powerplant has become “number two.”