The burning Supercars parity questions answered

Supercars is a technical parity formula. The cornerstone of the series is that a well built, well set-up and well driven car can win any race, regardless of the badge that's on the front.

In some ways, parity has become a simple prospect to achieve over the years. As the cars have become more controlled, there are less factors that need to be equalised. It was even easier at the end of the Gen2 era when it was Ford vs Holden and both cars were powered by five-litre, pushrod V8 engines.

What the controlled nature of modern Supercars has done, however, is shine a light directly on the big ticket items in parity. In Gen2 it was aero and Centre of Gravity. With Gen3 you can throw engines into the mix.

Given there is so little room to move elsewhere, small imbalances in these key areas have become significant performance factors – and led to some bitter rows over parity.

In 2018 it was the ZB Commodore and its composite panels (with the CoG benefits that came with them). A year later, along came the Gen2 Mustang with even better CoG and better aero than the category had ever seen.

Gen3 was meant to rein a lot of this stuff in by slashing aero and controlling even more parts under the skin. But instead we're locked in yet another discussion over parity, currently headlined by issues in equalising the 5.4-litre quadcam Ford motor, and the 5.7-litre pushrod Chevrolet unit.

Here, we'll attempt to answer some of the burning questions about parity in Supercars.

What is the issue?

As it stands the focus is on finding proper, unequivocal parity between two radically different motors.

Feedback from Ford drivers is that the motor lacks drivability, which in turn affects rear tyre life, while there is also a performance deficit at certain parts of the rev range.

Anton De Pasquale, Dick Johnson Racing Ford Mustang GT

Photo by: Edge Photographics

Under the hood of the Gen3 Mustangs is a 5.4-litre version of the production-based quadcam Coyote motors. The Camaros, meanwhile, are powered by a more bespoke 5.7-litre pushrod engine developed by KRE.

By its basic nature – electronically-controlled camshafts with variable cam timing, as opposed to a physical camshaft that needs to be machined to be changed – the Ford is the easier of the motors to manipulate in search of parity.

So, it is feasible that during the development phase, that was the path taken compared to re-machining camshafts for the Chevrolet motor.

This anomaly with the Ford engine, as it has been described by Supercars, could quite feasibly be a symptom of how the engine has been tuned to provide the power and torque numbers that, in the past, had produced parity between motors.

Why wasn't the alleged disparity spotted earlier?

Engine parity isn't something we've heard about in Supercars for some time, so it's understandable that the systems in place were thought to be robust enough.

The cornerstone of engine parity is the Accumulated Engine Power, which measures power, split into increments of revs (50 rpm increments at 200 rpm per second ramp) over a specified rev range.

The Gen3 motors both fall into the desired AEP range, while other key indicators such as torque and economy figures on the static dyno all paint of a picture of parity. And if both engines were pushrod engines with the same displacement, and a mechanical throttle linkage to individual throttle bodies, they would be even.

Even when there have been quadcam engines in Supercars in the past, such as the Volvo, Nissan and AMG units, consistency in displacement and bore and stroke all meant the AEP was a relevant measure of parity.

However, throwing these Gen3 cars into the heat of competition has exposed that, perhaps, the existing measures don't work flawlessly when you have two engines with completely different displacement and internal mechanics that react to inputs differently to each other – even if the ultimate output is the same.

The quadcam Ford Coyote V8 that powers the Gen3 Mustang.

What happens next?

So far work on equalising the engines has been focused on mapping changes and fiddling with the shift recovery.

Beta testing on various maps for the Ford engine took place in practice in Perth and Tasmania, with the Mustangs settling on what is known as the V2 map with a 30 millisecond shift cut for the latter. For reference, the Chevs use a 105 millisecond shift cut.

A version of the V3 map that was tested in Tasmania is now being assessed for use in competition from Darwin onwards.

Critically, most teams are set to use a test day between now and the Darwin Triple Crown, which will help Ford Performance and Supercars trial and assess options before the trek north.

But while the mapping changes are useful for issues such as the drivability, few are expecting a silver bullet solution to arrive until Ford and its teams are happier with the data on offer. And that's where the transient dyno comes in.

The transient dyno – which tests motors complete with the transaxle – is simply a more comprehensive tool to understand exactly what this anomaly with the Ford engine is.

Supercars recently assessed a transient dyno located at DS International in Melbourne, which is expected to host testing at some point in the middle of the year.

Another source of data will be torque sensors that will be fitted to the cars. They have been ordered by Supercars but won't arrive until at least the Townsville 500 in July, or perhaps even the Sydney SuperNight in August.

It is hoped these tools can uncover, in detail, where the alleged disparity lies.

Camaros have crossed the line first in every race so far this season.

Can parity ever be found between these two radically different motors?

The answer to that may well lie in what beefed-up data can be obtained through torque sensors and transient dyno testing. A more detailed picture of where the motors are at will hopefully allow Supercars to be more adventurous with changes – should they be required – than it currently, and understandably, is.

Despite the issues seen so far, there is optimism on both sides of the manufacturer divide that technical parity with these engines is possible.

The key will be the shift cut. There's a reasonably widely-held view that once the two motors can compete with the same shift recovery delta, technical parity has been achieved. For now, the longer shift cut on the Chevs is a bandaid solution.

Is Erebus suddenly winning because of parity?

Erebus Motorsport CEO Barry Ryan has been quite outspoken about parity issues being nonsense. Former Triple Eight boss Roland Dane has aired similar views in the press as recently as this week.

These are somewhat predictable responses. T8 is the GM homologation teams and responsible for 90 per cent of the Gen3 platform, so of course it is protective of these new cars. And Erebus is the team that has burst out of the Gen3 blocks. The team is currently the clear class of the field and has two drivers right in title contention.

Will answers on engines end the parity debate?

Now this is an interesting question. We've already seen some parity tweaks unrelated to engines take place this season, with the Camaro aero package tweaked before Newcastle before there was a CoG change to Camaros before Perth.

Since then, these engine issues have hogged the limelight. But there are still whispers from multiple Ford drivers, from multiple teams, that the Camaro package is still better balanced – and that an engine fix may not solve the rear tyre life issue by itself.

Cam Waters hinted at that following the Tasmania SuperSprint: "I can only speak for my car, and what I do inside the car, and to extract a lap out of it you're sliding and you're using all of the tyre.

"Sometimes when you put a green tyre on in quali it masks some of your problems, you can get away with having little issues. But in a race distance you can't do that. You have to [hold] the car back, or if you do drive faster, you know you're going to blow the tyre off it.

"We made gains for drivability [of the engine] between Perth and [Tasmania], and we probably need that again, I think. The might help a bit of our tyre life stuff. But I think there's more going on than just the engine."

This one is a classic case of watch this space.