Sebastien Buemi and Brendon Hartley have described the issue they encountered during the Total 6 Hours of Spa which cost their Toyota TS050 Hybrid time and put it “a bit out of touch” with the winning sister car.
The No. 8 Toyota that led the opening stages in the hands of Buemi encountered an engine-related problem that involved the car automatically entering a ‘protection mode’ to preserve its drivetrain.
This issue was first noticed when Buemi suddenly slowed during the first hour, although the Swiss driver had built up enough of a lead over Mike Conway to remain ahead.
After the Toyotas swapped positions coming off a second-hour safety car, Hartley was also affected by the same problem in the middle portion of the race.
Buemi admitted that he was “a bit disappointed” with the issues that dampened the No. 8 Toyota’s challenge at Spa, considering it had a slightly more favorable success handicap to the No. 7 machine driven by Conway, Kamui Kobayashi and Jose Maria Lopez.
“It’s been a tough race for car No. 8 today,” Buemi evaluated.
“I had a very good start and was able to take the lead but then we had lots of small problems and issues. We did not deal with them properly.
“I slowed down massively in Turn 18 and lost eight seconds. I could not restart; we had a little issue with the boost. And then we basically had that issue quite a few times going to the box and also exiting the box with Brendon.
“Because of that, we were a little bit out of touch with car No. 7. They did a very good race with no issues.
“I’m a bit disappointed with all of the small issues we’ve had today.”
Hartley also described his experience of the ‘protection mode’ activation, which cost him more time than Buemi.
The New Zealander said that he lost around half a minute to the power loss, which benefited Kobayashi who was able to restore some of the healthy lead he himself had lost during a safety car midway through the third hour.
“We had the battery level going down,” noted Hartley. “At a certain point with the system, it didn’t allow us to accelerate because we got the battery too low.
“It’s something the guys have to review; I’m not sure if they had this issue before. But it’s better that it happened today and not at Le Mans.
“It was a bit of a safety mode to protect the drivetrain. We have to do a little bit of investigation on how to ensure that doesn’t happen again but I’m sure the guys will be on top of it and no worries for Le Mans.”
Toyota Gazoo Racing technical director Pascal Vasselon revealed that both cars encountered the issue, but the timing and severity of the No. 8 machine’s problem was greater and consequentially resulted in it losing more ground in the race.
While a fifth-hour safety car tightened the gap and re-entered the No. 8 car into contention after Nakajima put pressure on Lopez, a late fuel splash for Buemi meant the Toyotas were ultimately separated by 34 seconds at the finish.
“We know that in some circumstances, as the engine went into protection mode, it took longer to get out of it on car No. 8 than car No. 7,” said Vasselon.
“On car No. 7, because it happened after car No. 8, they have been faster to react when it occurred. It was a bit more severe on car No. 8 and it happened to them first.”
Rain was Crucial for Overcoming Rebellion
Vasselon added that the wet conditions experienced during Saturday’s contest helped Toyota to ward off Rebellion Racing which started from pole and set the practice pace.
Rebellion’s R13 Gibson endured a difficult six hours and struggled with grip when the track was slippery. In the end, the Swiss privateer didn’t pose a threat to Toyota.
“We were expecting [Rebellion to win] because it would have been logical in a dry race,” said Vasselon.
“We were hoping for the rain, because a rainy race always offers opportunities, so we were quite happy to start in the wet, and we did our best to manage it.
“We were happy to have rain conditions because in the dry we would have probably lost the race.”