Triple Eight Race Engineering’s Ford Mustang during the Bathurst 12 Hour in February. Image: InSyde Media
Supercars undertook barometric testing on Ford, Chevrolet and Toyota engines at its Brisbane engine shop from Saturday to Tuesday.
A report was distributed to homologation teams on Wednesday night, with Supercars officials undertaking consultations in the paddock Thursday morning.
It’s understood the testing showed the Ford engine to be worst impacted by the barometric pressure at Bathurst, followed by the Chevrolet and then the Toyota.
Speedcafe understands Ford teams are expected to receive a larger restrictor – 52mm replacing 50mm – and a camshaft timing change.
There will be no changes to the Chevrolet or Toyota.
Supercars motorsport boss Tim Edwards confirmed the decision in a note sent to teams just under an hour before the start of Practice 1.
The change will be in place for Bathurst only, with the Ford to revert to its previous specification for the Gold Coast 500.
“As you’re aware, Supercars have conducted Barometric engine testing over the last 12 months and recently completed a further test,” it read.
“The results of this test have been provided to the Homologation Teams following which consultation has taken place.
“The testing has identified a power loss on the Ford at lower Barometric pressure and as such Supercars have approved a change of ESD developed by the Ford Homologation team to correct this for the Bathurst event only.
“No change is required to either the GM or Toyota.”
It’s expected that only one of the larger restrictors will be available to each Ford team for opening practice at 1:30pm local time.