F1 | Engine knock control: the new rule will be a test priority

Among the numerous new features of the 2026 regulations, there is one that has gone unnoticed, despite being of extreme importance. This is the crackdown on sensors in the combustion chamber, which will make it more complex to exploit the combustion engine to the limits of its possibilities. An exemption will allow manufacturers to exploit the tests to develop new control strategies, in order to prevent breakdowns throughout the year which, according to some, with the budget cap could even compromise the possibility of going on track. The new norm Frederic Vasseur was clear about what will be the priority for everyone at the tests: “The most important thing is to accumulate kilometres, not chase performance. We need to go around to verify the technical choices on the car in terms of reliability and then work on performance.” The need to run continuously is the reason why several teams have organized a private shakedown, so as to immediately identify any technical problems and then arrive in Barcelona ready to complete laps. The focus is entirely on reliability, since bench tests of the power units do not allow the conditions encountered in the real world to be faithfully replicated. An example is the vibrations to which the car is subjected while driving, which are particularly dangerous for the battery and other electrical elements, but not only. Another aspect is the episodes of detonation of the combustion engine, on which the ability to exploit it to the limit of its possibilities depends. Photo by Darko Bandic / POOL / AFP via Getty Images The power squeezed out of the engine also depends on its use mapping, i.e. on the adjustment of parameters such as turbo pressure, valve opening, composition of the air-petrol mixture and spark plug ignition to optimize the combustion process. However, all this must respect a physical limit, the so-called detonation, known in English as knock. This is an anomalous combustion that is triggered under certain pressure and temperature conditions, accelerating the wear of the engine and shortening its life. Until 2025, engine engineers could measure the pressure directly in the combustion chamber to monitor this limit, calibrating their maps accordingly. However, with the new regulations this will no longer be allowed. How control changes From 2026 the measurement frequency of the sensors in the combustion chamber is limited to 1 kHz, effectively preventing pressure peaks from being recorded and detonation monitored. Engine manufacturers will have to resort to an alternative strategy to control episodes of anomalous combustion, using accelerometers that measure engine block vibrations. It is therefore a question of developing a new model which, through vibrations, allows us to estimate the detonation limit, a work which has already begun on the bench, but which will have to be validated on the track with the disturbance of real world conditions. Exceptionally, in the collective tests of this first year, engine engineers will still be able to fit pressure sensors, so as to correlate the old and new control strategies. It will therefore be essential to make the most of the time available, developing a robust model that gives the necessary security to exploit the engine to its limits throughout the year without fear of failure. Reliability, on the other hand, will be an even more important issue than in the past, having to respect the cost cap. Through the ADUO mechanism, the FIA ​​has set up an extra budget for those who will be forced to replace multiple engines during the year. Among the experts, however, there are those who believe that this is insufficient, fearing the specter that someone will find themselves forced in an emergency situation to choose whether to exceed the spending ceiling, halt development or give up running.