The Australian 2023 Supercars Championship got underway with the Newcastle 500 on March 12; the first clash of the brand new ‘Gen 3’ cars from Ford and Chevrolet. After nearly 30 years of 5.0 litre V8s both cars have a new engine package.

The Ford Gen 3 is the Mustang GT S650 developed by Dick Johnson Racing and its engine is a naturally aspirated 5.4 litre Coyote V8. This is an aluminium four valve per cylinder, double overhead camshaft, fuel injected unit replacing the previous pushrod two valve per cylinder iron block V8.

With Gen 3 the Chevrolet brand replaces Holden, which GM has retired. The Chevrolet car is a Camaro ZL1 as developed by Triple Eight Race Engineering. Its engine is a naturally aspirated fuel injected 5.7 litre LTR V8, an aluminium continuation of the Small Block replacing the previous iron block generation.

The fact that the GM engine displaces 5.7 litres versus of 5.4 litres of the Ford reflects the fact that the former is a pushrod 16-valve unit and the latter a 32-valve with double overhead camshafts. On top of that these Gen 3 engines are far closer to production units than the outgoing 5.0 litre units, which are almost entirely bespoke.

Supercars expressed a desire to have more ‘manufacturer DNA’ in the Gen 3 engines for marketing and cost reasons. The previous V8s cost upwards of Aus $130,000 whereas the new ones are reckoned to come in at around half that with rebuild costs lowered too.

Under Gen 3 regulations these engines are confined to around 600 bhp where the previous ones were over 650 bhp. The lower power output and the larger displacement imply lower stress, hence higher mileage. The previous engines had a mileage of around 4000 km whereas the new ones have an initial target of 5000 km to be extended to 10,000 km in due course.

With these new engines Supercars has stopped engine development. Both engines have had to be homologated and each has to come from a designated engine builder - KRE Race Engines for Chevrolet  and Mostech Race Engines/Herrod Performance Engines for Ford.

Those builders will supply via the organiser, which will check each engine is within tolerance before randomly allocating to the respective marque’s teams. During the season Supercars will dyno test used engines to help assess the rebuild mileage requirement.

Gen 3 is the largest architectural change in Supercar’s history and came with significant effort to ensure technical parity was maintained. As part of the homologation process Supercars considered the power, the fuel efficiency, the weight, the centre of gravity height and the moment of inertia of each engine.

In a quest for engine parity Supercars measured the engines from Chevrolet builder KRE Race Engines and Ford builder Mostech Race Engines/Herrod Performance Engines over more than 1000 hours of dyno running.

Australian racer turned broadcaster Mark Larkham was given access to the testing and came out with praise for the parity the organiser had obtained. “These are two completely different engines,” he said.“We’ve had to get horsepower the same, torque the same, fuel usage the same. The power and torque curves literally overlaid and fuel usage, down to about one percent. They have absolutely nailed it."

But while Ford said ahead of Newcastle it was confident it had aero parity with Chevrolet it was not so confident of engine performance parity, given the considerable differences in engine architecture. Ford global motorsport chief Mark Rushbrook noted, “while you can meet on the dyno, how they perform in the car can be different.”

In the event of any engine disparity revealing itself in early season races the organiser has the tools to address that, mainly via engine calibration. Interestingly at Newcastle Triple Eight Race Engineering struggled with cabin temperature and put part of the blame on the switch from iron to aluminium for the block!