Among the rumours circulating in the paddock, there is not only the controversy triggered by the alleged increase in hot compression ratios of Mercedes and Red Bull engines. There are also persistent whispers about a possible new way of managing the turbocharged six-cylinder engine: using fuel to generate electrical energy. Let us try to understand how this could work.
There has been a great deal of discussion about the turbo lag that Formula 1 engines are expected to suffer next year, as they will no longer be able to rely on the support of the MGU-H, the motor generator unit that recovered thermal energy from the exhaust gases and converted it into electrical energy. That electrical energy could also be used to reduce the response time of the turbocharging system.
Some manufacturers, at the design stage, have tried to limit turbo lag by choosing a smaller turbine. The intention is to exploit the availability of electrical energy mainly on the straights, when the car is running at full power, in order to reduce the amount of lift and coast that is necessary to recharge the battery. This is because the energy recoverable during the braking phase will not be sufficient, especially on certain circuits, to guarantee electric power for an entire lap.
Since, in the new power unit configuration, both the internal combustion engine and the electric motor will each be capable of delivering 50% of the total power, finding oneself at the most critical moment with an empty battery would be equivalent to running with a power unit missing 350 kW. This would create an excessive performance disparity, potentially leading to very large speed differences at the end of the straights and possibly causing dangerous situations.
This is why some engineers have considered acting in a different way, possibly even compensating for part of the turbo’s delayed response by making a different use of the MGU-K.
The question is: how can this be achieved? In Formula 1, no knowledge is ever truly discarded. What was no longer considered useful in the past could become relevant again today. Do you remember blown exhausts? With specific engine mappings, such as retarded ignition and partially open throttles, engineers injected extra fuel into the exhaust in order to maintain a constant flow of hot gases, which helped to increase aerodynamic downforce. This solution, widely used at the beginning of the 2010s, was later banned.
Today, engineers could use special engine maps that, when the driver is in a lift-off phase, such as during cornering or through a chicane with partial throttle, would allow part of the energy produced by the six-cylinder engine to be directed to the MGU-K. This energy could be used to recharge the battery and at the same time limit the negative effect of turbo lag.
We will therefore have to get used to the idea of hearing some internal combustion engines delivering power even with the throttle closed. It will be interesting to discover who is developing these kinds of solutions for the combustion unit. Mercedes is often mentioned, but so are Red Bull Powertrains and Audi. We should not forget that the manufacturer from Ingolstadt won the most recent Dakar Rally with the RS Q e-tron, which used the DTM-derived four-cylinder turbo engine to power the MGU05 electric generator from Formula E, through a third electric unit.
The application was obviously very different, but the underlying concept is comparable. We should therefore prepare ourselves to see power units that differ greatly in the way energy is managed. It will be fascinating to understand which approach will prove to be the most competitive under the new technical regulations.
In essence, it could become possible to use fuel to generate the missing electrical energy. Will it be better to have a slightly heavier car in order to enjoy greater electrical availability that can be distributed over the course of a lap, or to focus on a lighter car that might suffer from occasional gaps in energy delivery?
It is clear that electronic management will be crucial, and that artificial intelligence will be required to develop complex strategies using specific algorithms.
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