The US-Spec Chevrolet Camaro ZL1 Was Too Loud For Australia

Holden Special Vehicles had to modify the American-made Chevrolet Camaro ZL1 in a number of ways in order to ensure it adhered to local Australian laws.

Sadly, one of those changes involved making the supercharged muscle coupe’s exhaust quieter, as WhichCar.com.au reports.

The loud exhaust note produced by the supercharged 6.2-liter LT4 V8 found in the Camaro ZL1 meant the car had to muffled quite considerably. In order to meet the Australian Design Rule (ADR) regulations for drive-by vehicle exhaust volume, HSV had to fit the car with a number of resonators. Manual cars must be slightly louder than those equipped with the GM 10-speed automatic transmission, as they had to be fitted with four resonators as opposed to just two for the automatics, Wheels indicates.

Automatic cars are allowed to have a max exhaust volume of 74 dB during the drive-by ADR test, while manual cars can be slightly louder at 75 dB max.

The 6.2-liter LT4 V8 in the HSV Camaro ZL1 is identical to the US-spec engine and makes the same amount of power, although Australian publications quote the car as making only 640 horsepower, as it is measured to European standards.

The Camaro ZL1 also wears different rubber in Australia, as its factory Goodyear Eagle Supercar F1 tires could not pass an Australian-specific test that involves braking with one side of the vehicle on slippery tile and the other on grippier concrete. Instead, it has Continental ContiSportContact 5P tires from the factory, with the Goodyears offered as a $1,000 AUS option.

The HSV Camaro ZL1 starts at $111,000 AUD locally.