McLaren racing director Eric Boullier has described the cause of a lack of running earlier in pre-season testing as “a stupid bolt” that failed.
Having missed out on a chunk of track time when Fernando Alonso crashed on Monday morning – when a loose wheel nut was to blame as the right-rear wheel detached – that was followed by Stoffel Vandoorne spending most of the afternoon in the garage on Tuesday as an exhaust clip broke.
With Vandoorne enjoying a much more productive final day of the test – completing 110 laps before handing over to teammate Alonso – Boullier revealed the extent of the exhaust issue.
“It’s a stupid bolt which broke in the exhaust,” Boullier said. “It’s a $3 problem which cost us a lot of track time. Everything was burned, so we had to rebuild the back of the car. It didn’t cost us much to revise the design, it’s more about the track time lost. As you can see the design is still the same and the car is still running.”
Boullier hinted McLaren has also had to work on the cooling of its new Renault power unit, with some burn marks seen on the rear bodywork before Vandoorne’s stoppage on Tuesday.
“The cooling is one of the first matters every team is managing in the first week of testing. In the case where you have a new engine partner, you might have some sort of heat soak pockets in the car – nothing else, to be honest.
“We can see on the bodywork there is a couple of stripes; this is just because we have to work on making sure there are some proper heat shields in place and consider all of the heat soak pockets I mentioned and make sure we can modify and change the cooling internally or inside the bodywork.”
As well as completing significant mileage on Thursday, McLaren was also quick as Vandoorne ended the day second fastest to Lewis Hamilton and Alonso posted the fifth-fastest time.