Mercedes and the PU 2022: “Problems with delivery and driveability” | FormulaPassion.it

The Mercedes power unit was the most reliable of the whole lot last season. In fact, several cars equipped with Brixworth engines completed the championship without exceeding the limit of three seasonal units, the only ones to do so on the grid. However, reliability and power are just some of the parameters that certify the goodness of a power unit. In fact, Toto Wolff explained that, in addition to the aerodynamic and chassis problems, the 2022 W13 also sufferedand a grumpy engine to check in regards to driveability.

“During the year we also had some problems with the power unit”, emphasizes Wolf. “We were dissatisfied with things like power delivery and handling. Despite the development freeze, the engine team still managed to fine-tune the performance, juggling a difficult environment in which the car’s rebounds broke the engine. Despite this, we were extremely reliable and the engine worked well until the end of the season.” The Brixworth power unit showed flaws in the thermal and electrical power delivery curve, with an imperfect pedal response reactivity or vice versa an excessive aggressiveness during acceleration depending on the speed. An engine with poor driveability also puts more stress on the rear tyres, complicating the management of wear and temperatures. Hywel Thomas, head of the Brixworth engine department, identifies the switch to fuels with 10% bio-components as one of the possible causes: “At the start of the season, the first big thing to address was that the power unit would be frozen for the next four years. The second change was fuel regulations. We knew she was going to hit us, just as she was going to hit others. With these news we didn’t know in which position we would find ourselves. When we took to the track there was a bit of disappointment”.

The development freeze prevented Mercedes from working on the hardware, i.e. on the concrete components of the power unit. However, the Brixworth engineers managed to work on other aspects, especially on the software side, to improve the performance of the power unit, not strictly in terms of power, but rather in terms of driveability. Spark plug timing, turbo control with the MGU-H, hybrid charging strategies and even software control of batteries and electric motors allowed small gains to be found race after race. Thomas especially pointed out i progress in terms of deployment, placing the emphasis on the team’s ability to find more fractions of energy that can be exploited with the hybrid system. Equally important was the integration between engine behavior and chassis requirements: “What transpired in all of this is the importance of the link between the frame and the power unit. They cannot be developed separately. If you want to find performance from the engine without being able to intervene on the components, the power unit must marry even better with the chassis. This is the area where some of the biggest progress has come, especially in the second half of the season.”

Thomas finally commented on the repercussions of porpoising on the power unit. The rebounds of the W13 in fact caused major shocks to the engine: “It was clear that the underside of the bottom was taking a beating. When we saw some parts at Brixworth that were on race engines, it was quite surprising how many hits they took to the ground. When we saw Lewis and George getting out of the car not really comfortable because of the porpoising, it was more of the same for the power unit ”. Nonetheless, the Brixworth power units were the most reliable ever, a major strength from which to start again in 2023.