Stewards report: Percat tyre pressure decision

Nick Percat

The following is the full stewards report, as released to media, concerning the penalty for Brad Jones Racing over a breach of tyre pressure regulations on Nick Percat’s car in Race 12.

Stewards decision

Number 29

Document: 19



Hidden Valley Raceway, Darwin, Northern Territory

17th to 20th June 2021

The Stewards, having received a report from the HoM, having heard from the DRD, the Authorised Representative of Brad Jones Racing (BJR) (and with the consent of the DRD, the Team Principal of BJR), and having received telemetry data from the HoM and the Supercars Technical Lead Engineer, have considered the matter and determine the following

Competitor Brad Jones Racing Pty Ltd

Car and Driver Car 8 Nick Percat

Date Saturday, 19 June 2021

Session Race 12

Rule D17.1.17 The permitted pressure of a Control Tyre when fitted to a Car is 17psi which must be achieved at any time that the Car is on the Circuit during any Session.


During the Hearing conducted by the Stewards after Race 12 the following facts were agreed by BJR and the DRD and acknowledged by the HoM:

  1. When Car #8 passed the Pit Exit Line to start the Observation Lap for Race 12, the pressures of all 4 Control Tyres fitted to Car #8 exceeded 17psi and were consistent with the pressures at that point in time on Control Tyres fitted to other Cars in Race 12;
  2. The Engineer for Car #8 warned the Driver of Car #8 against excessive use of the brakes on Car #8 on the Observation Lap;
  3. When Car #8 stopped on the Grid at the end of the Observation Lap the pressures of all 4 Control Tyres fitted to Car #8 exceeded 17psi but the pressure increase achieved between the Car leaving the Pit Exit Line and stopping on the Grid was nominal and less than the pressures of Control Tyres fitted to other Cars in Race 12 (which was consistent with the Driver of Car #8 having used very little braking on the Observation Lap);
  4. Car #8 sat on the Grid for over 15 minutes before the start of the Formation Lap for Race 12. During this time Control Tyres on the left side of Car #8 faced the sun whereas the Control Tyres on the right side of Car #8 were in shade;
  5. The Team Engineer for Car #8 noticed that the pressures of the Control Tyres on the right side of Car #8 had dropped to below 17psi. He approached the HoM and disclosed this problem. TPMS telemetry from Car #8 confirmed that the pressure of the front right Control Tyre was 16.8psi and the pressure of the rear right Control Tyre was 16.6psi. Because the HoM could not exclude the possibility that these 2 Control Tyres had lost pressure due to punctures or some other fault, he granted permission for BJR to change to two right wheels on Car #8 while it was on the Grid but warned BJR that he would take possession of the wheels and Control Tyres removed and if subsequent investigation revealed no puncture or fault with either of them, he would report the Incident to the Stewards. These two wheels were changed by BJR;
  6. Given the time constraints, the mechanics for Car #8 had overlooked bleeding excess air out of the replacement Control Tyres such that the pressures on these Tyres significantly exceeded the pressures of Control Tyres on the left side of Car #8 and what would be expected of any other Control Tyre fitted to any Car on the Grid;
  7. Car #8 left the Grid to start the Formation Lap for Race 12 and started Race 12 with the pressures of all 4 Control Tyres fitted to the Car exceeding the prescribed minimum of 17psi. Car #8 therefore complied with Rule D17.1.7 at all times throughout the Race. The pressures of the Control Tyres on the right side of Car #8 when it started the Formation Lap were so high that it would have resulted in a performance disadvantage for Car #8 at the start of Race 12;
  8. During the Race the pressures of the Control Tyres removed from the right side of Car #8 when it was on the Grid were monitored by the Supercars Technical Team and no punctures or other faults were observed which would explain an unanticipated loss of pressure in those Control Tyres on the Observation Lap.


Loss of all 2021 Repco Supercars Championship Teams Points for Car #8 in Race 12.


Rule D17.1.17 was breached. However, the breach was remedied before the start of Race 12. That only happened because the Team had identified the non-compliance and received the approval of the HoM to address it by changing the right wheels and Control Tyres on Car #8 when it was on the Grid. By so doing the HoM was not absolving BJR from the breach, only giving the Team the benefit of doubt in his mind whether the low pressures were attributable to a fault.

Because it is within Division D of the Rules, Rule D17.1.17 is a Sporting Rule unlike the Rules in Division C which are Technical Rules. A breach of a Technical Rule must result in the Disqualification of the Car concerned. That result is not an automatic consequence of a breach of a Sporting Rule even if the Sporting Rule has a conformity element to it.

Rule D17.1.17 serves an important safety and sporting function. The lower the pressures in a Control Tyre the longer the Car can run on those tyres in a Race but if the starting pressures are too low it creates a risk that the tyre may dislodge from the rim. The Rule was introduced to avoid this risk.

Historically Teams were permitted to adjust the pressures in Control Tyres while a Car is on the Grid. However, this was recently prohibited. Consequently Teams must now pre-set the pressures in Control Tyres before the Car leaves Pit Exit to start the Observation Lap. Obviously, in so doing Teams attempt to ensure that in the period between leaving Pit Exit and the start of the Formation Lap the pressures do not fall below 17psi but do not greatly exceed that minimum. With a 30 minute start procedure which means Cars will sit on the Grid for some time, predicting pressure loss is not without difficulty.

In this case the Team erred. The Team’s strategy was to attempt to ensure that the pressures of the Control Tyres on Car #8 were as low as possible at the start of Race 12. The communication between the Engineer and the Driver of Car #8 was aimed to achieve that strategy but it was followed by the Driver to an extent that the Engineer hadn’t anticipated.

This is an unusual set of circumstances. Because Car #8 complied with the Rules throughout the race (even though it did not comply before the race started), we are satisfied that a Penalty of Disqualification would be disproportionate. However, a Penalty is required. The Rule was breached and the breach would have resulted in Disqualification had the Team not disclosed the non-compliance to the HoM and it was detected during the race or had the HoM refused permission to change the non-complying Control Tyres.

The DRD recommended to the Stewards a Penalty of the Loss of all Teams Championship Points for Car #8 in Race 12. The Team were prepared to accept that Penalty if the Stewards found the Rule to have breached (which we have). In our view, the DRD’s recommended Penalty is appropriate to the circumstances. It will serve as a discouragement to Teams against employing strategies to run so close to the edge of the Rules in the expectation that they will be immune from consequences if they get it wrong.

The Competitor is reminded that Decisions and Penalties that may be subject to Appeal are set out in B7.7.2 and the Rights to and process for an Appeal are set out in B5.

Issued by the Stewards of the Event:

Matt Selley (Chair)

Steve Lisk

John Leahy

Motorsport Australia Supercars Stewards

DATE: 20 June 2021 TIME: 0845hrs

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