Mercedes have made a raft of changes for 2021, aimed at addressing reliability concerns with their power unit and energy recovery systems. Mercedes have launched their new W12 for 2021, with Technical Director James Allison explaining the areas of the chassis and aerodynamics the team has concentrated on finding improvements for this year.
However, the power unit regulations haven’t been quite as restrictive as those affecting other areas of the car. As a result, Merc’s High Performance Powertrains have been able to work hard on finding areas of development and also been able to address areas of concern with their power unit package.
“We are going into the eighth season of pretty stable regulations, so we have a good understanding of the current hybrid engines.” explained Hywel Thomas, Managing Director of Mercedes High Performance Powetrains.
“Our new product is a characteristic Mercedes-AMG Power Unit, but we’ve worked hard to take the next development step. Stable regulations mean that it’s getting increasingly challenging to unlock additional performance, so you need a focused approach. We identified three main areas to work on: first, 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.”
“The second area is reliability. We discovered some design issues last year, so we’ve been looking at those and introduced some changes to address them. And we’ve also got some completely new innovations that will be in the racing PU for the first time. 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.”
Thomas went on to explain where the team have unlocked some performance and reliability, including a change in the material used to make the block itself.
“We’ve continued our quest for better thermal efficiency in the Internal Combustion Engine.” continued Thomas.
“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 the heat rejection. Those are probably the most striking when it comes to crank power and the performance of the Power Unit. We’ve also completed some work on improving the reliability of the PU. 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, 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.”
A constant area of concern in 2020 was with the MGU-K, and this is a component HPP have sought to redesign with the aim of stamping out any further reliability issues. “We introduced a complete redesign in 2020, a very different MGU-K to what we had run previously. 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.”