Supercars announce gravity parity rule

Supercars has taken the first step to reining in the runaway Mustangs by announcing a new centre of gravity parity rule.

From next month’s Tasmania SuperSprint at Symmons Plains, all cars will have the same CoG position, as mandated by Supercars technical officials.

The new two-door Fords’ CoG will be raised significantly, while the ZB Holden Commodores’ will also be lifted, with both adjusted to match the unchanged Nissan Altima.

Following the uproar over the Mustangs’ domination of the first six races in Adelaide and Melbourne, Supercars conducted a two-day test to measure the centre of gravity of all three models.

Ten cars representing a mix of all three models were held back after the Melbourne 400 at the Australian Grand Prix to have their CoGs measured by a technical team led by new head of motor sport Adrian Burgess at Kelly Racing’s expansive facility at Braeside in the south eastern suburbs.

The test was undertaken because rival teams were convinced the DJR Team Penske and Tickford Racing Mustangs had gained an unfair advantage with a lower CoG, which is achieved by concentrating weight as close as possible to the floor.

The lower the centre of gravity, the better is a car’s cornering performance.

The CoG row has its roots in the ZB Commodore, which achieved an improved placement of mass due to its unprecedented use of lightweight composite body panels and under-the-skin structure.

In response to an outcry from Falcon teams and the then factory-backed Nissan squad, the FG X and Altima were quickly allowed to replace their metal roofs, bonnets and boot lids with lighter composite replicas.

But the Mustang has moved the CoG limbo on, with the combination of its smaller coupe glasshouse and an aggressive design program to place more weight – including ballast – lower in the common Supercars chassis resulting in a major gain.

Following the comparative test, the CoG data was analysed by the Supercars technical department and forwarded, with a recommendation for remedial action, to the Supercars Commission.

Following a meeting earlier this week to consider the findings, the Commission endorsed the adoption of a standardised centre of gravity location, which was then forwarded to and approved by the Supercars board of directors.

In a statement, Supercars announced the new CoG parity rule would be implemented at the next round at Symmons Plains from April 5-7.

“The Supercars Championship is underpinned by technical parity,” it said. That is, the sport seeks to minimise any technical differences between models of vehicle in the spirit of equitable competition.

Supercars does not pursue sporting parity, which seeks the equalisation of the abilities of participating drivers and or teams.

It is important to note the constitution of Supercars includes the premise that incoming models must meet the incumbents. The purpose of this is to ensure those new models do not unduly increase the costs for current teams in pursuit of technical parity.

It is this principle which has been the cornerstone of Supercars’ success, producing the world’s best door to door racing with cars competing within tenths of a second.

Because of this, Supercars as a Series, and the teams that compete within it, must use best endeavours to manage and uphold technical parity as much as is reasonably possible.

Each year construction methods and materials used in the development of Supercars moves on. Every new car, logically, brings a series of developments and changes. With those changes, which are within the rules, technical variances between models can occur.

The most recent example is the introduction of the Ford Mustang, the first two-door car to enter the Series. Similarly, the introduction of the ZB Commodore in 2018 brought with it new methods and materials.

On presentation of the Mustang at Adelaide, the Supercars technical department recorded a significant increase in ballast as compared to the previous model, the Ford Falcon.

To ensure competing teams did not have a technical advantage, the technical department, on instruction of the Commission, conducted centre of gravity testing on the 18th and 19th of March in Melbourne.

The results of the tests show that the Commodore and the Mustang had a Centre of Gravity advantage over the Altima. These results have been reviewed by the Commission and the homologation teams along with plans to address with the appropriate ballasting of the Commodore and the Mustang to maintain technical parity.

The same and equal change is being made to all models. That is to say, there is no change in relative performance between teams using the same model of vehicle, only a redressing of the technical differences between the models in accordance with Supercars’ constitution.

The proposal has been approved by the Supercars Commission and the changes will be implemented for Tasmania.

Supercars CEO Sean Seamer added: The success of Supercars is built on the closeness and spirit of competition. Like the ZB before it, the Mustang has advanced build techniques and technology.

All three homologated vehicles have been built within the rules.

The Supercars Championship is underpinned by technical parity. That is, the sport seeks to minimise any technical differences between models of vehicle in the spirit of equitable competition.

I compliment the manufacturers, homologating teams and the Commission for their positive approach to supporting technical parity across all models.”

While the CoG equalisation addresses one concern about the Mustang’s dominance, it is not the major worry.

The Holden teams and Kelly Racing are convinced the unbeaten Ford’s main advantage is a raft of aerodynamic tweaks.

Supercars will now scrutinise aero data to determine if the Mustang needs to be further hobbled before the April 12-14 Phillip Island SuperSprint at the high-speed oceanside circuit.