"Following an admission by WAU Racing Pty Ltd of a breach of supplementary regulation 6.2 – At this event... all cars are required to install the 'back Up #1 drop gear of 1.000 from the commencement of the .. event' , the stewards disqualified car #2 and car #25 from practice session 1," read the stewards report.
Teams were all ordered to move to the 1.000 final drive for this round, however the supplementary regulations also specified that:"Drop gear 1.074 as specified in Rule C10.5.1 for the Sandown International Raceway is also required to be on hand at the event". That appears to be what caught WAU out and led to the shorter drive being installed for the opening practice session.
WAU also copped a $500 fine for a wheel nut from Percat's car that wandered across the fast lane during pitstop practice in the third practice session.was clocked doing 50 km/h at pit entry, where the limit is 40 km/h, during the first session.