F1 | What Mercedes changed to solve power unit reliability issues
Mercedes' engine chief reveals power unit changes to address reliability concerns ahead of the new season.
Mercedes has taken off the cover of their new W12 earlier this morning. On this occasion, the engine chief Hywel Thomas explained how the team has addressed reliability concerns.
Last month the Brackley-based team revealed to encountering "issues" with their power unit for the upcoming season, however, Thomas believes they have put in place the necessary adjustments before the campaign begins.
At the car launch, Hywel Thomas has removed all doubts and explained in detail how the team has progressed. In particular, there have been changes in the materials used and in the energy recovery system.
"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.”
The proposed 23-race calendar poses a huge challenge for power units and on its reliability; nevertheless, the team’s engine chief is confident they’re hard work to improve on that area will pay off.
After perceiving that the concept they used last year was not ideal, one of the most relevant modifications that the team operated was revamping the design of its MGU-K. – Indeed, in 2020 they introduced a completely different MGU-K design, which proved to be very efficient but difficult to assemble.
"In 2020, we introduced a very different MGU-K to what we had run previously," Thomas said
"It helped us make a solid step forwards 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. 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 of the MGU-K."
Despite the short winter break, Thomas claimed that they updated their 2021 PU with a number of new features, which he hopes will allow making an even bigger leap forward in terms of performance.
"We've got some completely new innovations that will be in the racing PU for the first time," he said.
"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."
One of the major concerns that were raised last year, as a consequence of the German’s car manufacturer to race with an all-black livery, was related to the possible excessive heating of the cars. However, Thomas commented:
"We've continued our quest for better thermal efficiency in the internal combustion engine. Most of the developments can be found in the core of the power unit, with a desire for maximum output from the combustion process.
"Hand in hand with that, we've introduced changes to the turbocharger to minimise the impact on heat rejection. Those are probably the most striking when it comes to crank power and the performance of the power unit."