Mercedes reveals changes to 2021 power unit


Following the recent admission that the team had encountered "issues" with its 2021 power unit, engine chief, Hywel Thomas gives insight into how the world champions have reacted to the problem.

"We have got some issues with the power units," he admitted last month, "we know we have issues but we have plenty of plans in place to fix all of those issues.

"I'm sure it will all be ready for the first race," he added.

Speaking as the German team pulled the wraps off its 2021 contender, Thomas revealed how it has dealt with those issues.

"We've completed some work on improving the reliability of the PU," he said. "In 2020, we used an aluminium structure which wasn't as reliable as intended, so we've introduced a new alloy for the engine block. We've also made some adjustments to the Energy Recovery System, to make it more resilient.

"We've got a big challenge in 2021 with 23 races on the calendar," he continued, "we will need to ensure that the reliability of the power unit is spot on. We've worked hard on that area and hopefully it's paid off."

One area of concern, particularly in the latter stages of the season, was the MGU-K. In a bid to 'get around' the issue, the Mercedes runners turned down their power units, while, a week after his victory in the Sakhir Grand Prix, Sergio Perez was sidelined just 8 laps into the season finale due to an MGU-K issue.

"We introduced a complete redesign in 2020," said Thomas, "a very different MGU-K to what we had run previously. It helped us make a solid step forward in performance, but it was a design that turned out to be difficult to manufacture and assemble consistently.

"We had lots of examples where the MGU-K ran a full cycle and did exactly what we wanted it to do, but we also had some cases of midlife failures," he admitted.

"For 2021, we've gone back, looked at that design and built an understanding of where the failures have come from. We have changed it for this year, to allow for a more consistent manufacturing route which should help to improve the reliability.

Worryingly, for its rivals, Thomas is confident that once again, the Mercedes which has totally dominated the hybrid era will continue to be strong in the season ahead.

"Stable regulations mean that it's getting increasingly challenging to unlock additional performance, so you need a focused approach," he said. "We've continued the development of the technology in the power unit. That's a continuous process, and we feel like we've been able to take a step forward on that front again this year.

"We've also got some completely new innovations that will be in the racing PU for the first time," he added.

"That was particularly challenging because last season finished late, so the winter period has been shorter than normal and has given us less time to prepare, which put extra strain on the business."

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Published: 02/03/2021
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