The high-performance American muscle car completed the lap of the 20.8km circuit through Germany's Eifel mountains in a time that puts it ahead of supercars like the Ferrari 458 Italia (7:38), 991 Porsche 911 Carrera S (7:37.9) and Lexus LFA (7:38.85).
To date, only the Chevrolet Corvette ZR1 and the SRT Viper have set faster times for American cars at the infamous track.
The current production car record at the circuit was set last month by the Porsche 918 Spyder, which needed just 6:57, thanks to its 660kW hybrid powertrain.
The Z/28 makes do with a 377kW 7.0-litre V8, sending power to the rear wheels through a six-speed transmission.
Fade-free carbon ceramic brakes are also standard and assist in late braking.
The key to the stripped-down Z/28’s performance is re-engineering and a weight-saving program, however, that stiffens the chassis, removes sound-deadening material and uses thinner glass on the rear window.
There’s also no standard air conditioning (it’s an option) and only one audio speaker – required by law to provide a door chime.