Bahrain WEC: Audi makes changes after chassis damage

The R18s were found to have damaged tubs after their arrival in Bahrain from China for this weekend's Sakhir World Endurance Championship round.

Both cars took part in the two free practice sessions on Thursday after full rebuilds, but the #1 car was diagnosed with the same problem after the second, evening session and did not take part in Friday morning's practice period.

Audi Sport Team Joest technical director Ralf Juttner explained that the squad had "optimised" the mountings in a bid to solve the problem.

"We have optimised the way we mount the floors, but it is too complicated to go into detail," he said.

The #2 car came through Friday morning practice without a problem in this configuration.

The damage sustained to the monocoques is believed to have resulted from the R18s running over relatively flat kerbs that strike the centre of the car.

Audi Sport boss Wolfgang Ullrich said: "It seems that at flat circuits where we take the kerbs between the wheels that the car touches where it doesn't normally touch."

The #2 car, shared by championship challengers Andre Lotterer, Benoit Treluyer and Marcel Fassler, was rebuilt around the spare monocoque carried by the team.

The #1 Audi, driven by Tom Kristensen, Loic Duval and Lucas di Grassi, was built up around a tub that arrived at the Bahrain International Circuit at 3am on Thursday morning.

A second spare arrived at the track on Thursday afternoon and it is around this chassis that the #1 car is being rebuilt for a second time.

Audi opted not to undertake a second all-night shift, which means that the #1 car missed practice three and will also not take to the track during qualifying on Friday afternoon.