GM readying for parity change during NZ double-header

Supercars has introduced a new parity trigger system this year that uses race lap time data from all three marques.

The championship is required to undertake a parity investigation if there’s a significant delta between brands in six consecutive races.

Such a trigger is yet to occur, in part due to multiple races at Albert Park not being included in the calculation due to limited green flag laps.

GM is, however, expecting the trigger to be reached during this weekend’s Taupo Super440, paving the way for a change at Ruapuna.

Team 18 principal Adrian Burgess said a collaborative effort is already taking place to devise a change to the Camaro aero package.

“With all these processes, you look at the results over the time we’ve had and you prepare, you don’t just wait until the trigger is triggered and then you start doing the work,” Burgess told Speedcafe.

“So well done to Supercars. Them and ourselves started investigating a while back and we’ve been working with each other to identify where we see a deficiency and what rectification may be.

“That rectification, even at this point today, is still not locked in, what it may be, we’re working with them, working together, GM in the US and Jeromy [Moore], working there on a solution and obviously Supercars are with our CFD provider as well.”

The lap time based trigger requires Supercars to undertake an investigation to see if there is a technical discrepancy that needs to be addressed.

However, GM believes it already has grounds for a parity change based on data from last December’s wind tunnel testing.

The Camaro is said to have been signed off at Windshear with an aerodynamic balance slightly further forward than its rivals.

That was a knock-on effect of the Camaro having originally been slated as the baseline for the testing, to which the Ford Mustang and Toyota Supra would be matched.

However, the script was flipped midway through the testing and the Camaro was tweaked – resulting in the unwanted balance shift.

It’s said to have resulted in rear stability issues for the Camaros, a problem Ford runners complained of prior to their parity change midway through 2025.

Burgess said his team already has a some revised aerodynamic parts ready to go in NZ and can bring more in ahead of Rupauna.

“We’ve taken precautionary measures to have parts available if we’re in a position to be able to make a change,” he said.

“We’ve manufactured parts for all the teams. I’ve got some sat here and there’s some more parts on the way.

“But we don’t yet know what the configuration will be, so don’t ask me whether it’s A, B, C, D, because it’s not defined yet.”

Burgess said all of the parts that could be part of the upgrade package have been run in the wind tunnel and on track previously.