A statement from the FIA has revealed the reasons behind the changes made to the Lusail International Circuit overnight, with tyre manufacturer Pirelli Motorsport citing tyre integrity and safety.
The track limits for turns twelve and thirteen were revised, the track being narrowed on the exit of both turns in a bid to prevent cars from running over the harsh kerbing, with this requested due to issues with tyres on Friday in Qatar.
On a microscopic level, Pirelli identified some separation in the sidewall between the topping compound and the carcass cords, with similar findings up and down the paddock. The changes to the track meant the FIA allowed a ten-minute practice session to take place for drivers to get used to the new parameters around turns twelve and thirteen, prior to the Sprint Shootout session, which was delayed by twenty minutes.
It was the first additional session to take place in the FIA Formula 1 World Championship since the 1996 Monaco Grand Prix, which saw a session added after rain hit the track prior to the race.
With more investigations set to take place after the Sprint race on Saturday evening, should the issues continue, drivers will be mandated to run a three-stop pit strategy during Sunday’s main race to prevent issues rising with the tyres.
“Following the standard analysis of tyres used during Free Practice 1 yesterday, in which tyres that have been used for approximately 20 laps are examined by Pirelli to check various safety parameters, a separation in the sidewall between the topping compound and the carcass cords on many of tyres that were checked was discovered,” read the FIA statement.
“It is the view of the FIA and Pirelli that a significant number of additional laps on these tyres could result in circumferential damage of the tyres with subsequent air loss, and tyres analysed with lower lap numbers showed a much-reduced extent of the issue.
“This issue has likely been caused by the high-frequency interference between the tyre sidewall and the 50mm ‘pyramid’ kerbs used extensively at this circuit, aggravated by the propensity to ride those kerbs.
“The following actions will be taken on safety grounds in response to this issue:
- Track limits at Turns 12-13 will be revised.
- There will be a 10-minute Practice Familiarisation Session, scheduled to start at 16:00 local time, following the revision of the track limits, to allow drivers to adjust to the changes. The Sprint Shootout will therefore start 20 minutes later than scheduled (16:20 local time).
- There will extensive tyre analysis following the Sprint (19 laps), to decide whether further action needs to be taken ahead of the Grand Prix.
- In the event the problem is still evident, we will be issuing the following directive for Sunday’s Grand Prix, on safety grounds:
- The tyre life parameter must not exceed 20 for new tyres used in the race. This number would rise to 22 for any used tyres fitted in the race, to account for in-out laps in qualifying.
- All drivers will be obliged to perform at least three tyre-change pitstops during the race.
“Pirelli and the FIA will carry out extensive research and simulations in order to establish with complete confidence the reasons behind this issue, and to work on solutions to avoid it in the future.”
