Mostert technical breach explained

Mostert qualified on the front row for the third and final race at Sydney Motorsport Park on Sunday, only to be punted to the back of the grid for a technical breach.

Officials found that the front guard width exceeded the allowance in the Vehicle Specification Document for the ZB Holden Commodore.

While not arguing the breach itself, Walkinshaw Andretti United did attempt to explain that contact with a kerb left the car with broken mounts that pushed the guards out.

That there was contact with a kerb was proven by on-board vision, however the argument itself didn't satisfy stewards who proceeded with the disqualification following the hearing.

Penalties for non-confirming bodywork are rare in cases where panels have been dislodged by contact during sessions.

However Motorsport.com understands a lack of visible signs of contact was the key factor in this particular case.

Had there been physical damage to the panels more leniency may have been applied.

"Following a post-session hearing into a charge against WAU Racing Pty Ltd that car #25, Chaz Mostert, was in breach of Rule C2.1.1 (a car must comply with the design, relevant VSD, ESD, and the rules) because the width of the front guards was found by Supercars Technical at post-session scrutineering not to comply with the VSD for a Holden Commodore VB," read the stewards report.

"The stewards summonsed the competitor to a hearing and heard from the competitor, its driver and the [Head of Motorsport].

"The competitor gave evidence (confirmed by the driver and on-board vision) that the car hit the kerb at Turn 10 and this caused the damage to the car and resulted in the non-compliance.

"The HOM replied that if the damage was caused by hitting the kerb, then the setup for the car was a contributing factor.

"The stewards decided that they were not satisfied that the striking of the kerb (if it did create the damage) amounts to exceptional circumstances that would exculpate the breach nor amount to a mitigating factor justifying some other penalty other than the imposition of the usual penalty, namely disqualification for a technical breach (which is also the recommended minimum penalty)."

Mostert recovered to a fine third place in the wet and wild night race.