The 2023 Chevrolet Corvette Z06 is powered by a naturally aspirated 5.5-liter V-8 making 670 hp and 460 lb-ft of torque, making it the world's most powerful V-8 without forced induction, found in a production car. As this explainer from the Society of Automotive Engineers (SAE) shows, that's partly down to some 19th century physics know-how.
Code-named LT6, the Z06 engine relies on a phenomenon discovered by German physicist Hermann von Helmholtz in the 1800s. He observed that air vibrating in a closed chamber at a pressure slightly above atmospheric pressure produces sounds similar to guitars and whistles.
Today, that's known as Helmholtz resonance, and Chevy engineers harnessed it to generate positive pressure in the LT6 engine's intake manifold, helping to broaden the torque curve.
2023 Chevrolet Corvette Z06
The LT6's induction system consists of two molded nylon chambers, which get air from two 87-millimeter throttle bodies. Ribber mirror-image plenums are connected by three "communicator valves" operated by the engine's control module (the throttle is by-wire).
Two of the communicator valves open and close in tandem, while the third operates on different timing. Each plenum has four molded-plastic trumpets to feed the cylinders, which is then split by the intake runners to feed two titanium intake valves per cylinder. The mass of air causes pressure waves to reverberate through the intake system every time a valve closes on the compression stroke.
The communicator valves help maximize resonance within the intake system, harnessing Helmholtz's principle. At wide-open throttle, the paired valves stay closed until 2,000 rpm, while the third valve stays closed until 5,800 rpm.
2023 Chevrolet Corvette Z06
The result is a fairly flat torque curve up to the 6,300 rpm torque peak (horsepower peaks at 8,400 rpm). Volumetric efficiency—the measure of air and exhaust flow through an engine—is an impressive 110%, the SAE noted.
The LT6 uses plenty of other engineering tricks, including dry-sump lubrication and a flat-plane crankshaft, which gives the engine a sound that puts modern Ferrari V-8s to shame. While a top speed hasn't been verified, the Z06 is expected to do 0-60 mph in 2.6 seconds.
Z06 deliveries are expected to start this summer, with both coupe and convertible body styles on offer. Cars will be built at the same Bowling Green, Kentucky, factory as the standard Corvette Stingray, with engines assembled at the co-located Performance Build Center. The push for electrification means the LT6 likely won't stick around for long, so let's appreciate this feat of engineering while we can.
