F1, power unit updates and reliability: what is allowed for 2023 amid development freeze

The 2023 Formula 1 season will be the first time ever in which the development of hybrid power units will be entirely frozen compared to the previous championship and not just during the current season. Even in 2021, when the single-seater chassis was prone to development freeze, power unit manufacturers were still able to bring a new engine specification to the start of the year.

It was precisely on that occasion that Honda introduced the new engine one year early, a power unit that won the world title and proved to be the best engine of the turbo-hybrid era in terms of balance between power, compactness and reliability. 2023, on the other hand, will be radically different, with engine manufacturers forced to use the same power unit specification as 2022. Modifying combustion chambers, pistons, valve angles, turbochargers and hybrid systems to squeeze further horsepower will no longer be permitted and the PU architecture will remain largely frozen.

However, there are some secondary intervention opportunities, strictly regulated but still useful for trying to identify some marginal gains.

Firstly, as is well known, engine manufacturers will be able to make changes on the power units for reliability reasons, opportunities that Ferrari and Alpine are looking at with particular interest. The line between reliability and performance is very blurred, as a more robust power unit can be exploited with more aggressive mappings. For example, the Scuderia from Maranello operated in the second half of last season with a limited engine in order to avoid the technical failures suffered in the first part of the year, which is why an improvement in terms of reliability for 2023 will make it possible to use part of the unexpressed power.

The regulations for interventions on the reliability of the power unit are described in point 5.1 of appendix 4 of the technical regulations: “A manufacturer may submit an application to the FIA during the homologation period to make modifications to the homologated components of the power unit for the sole purpose of improving reliability, safety, costs, or by introducing minimal and incidental changes. […] Applications must be submitted in writing to the FIA Technical Department and must include all necessary supporting documentation, with clear and appropriate evidence of failures attached. The FIA will circulate the correspondence to all power unit manufacturers for comment. If the FIA, in its absolute discretion, is satisfied and deems these changes acceptable, it will confirm to the PU manufacturer in question that it will be able to proceed with the changes.”

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Point 5.2 of Appendix 4 instead regulates changes considered as minor: “Modifications can be considered minor if the component design is not affected by them and if the effects on reliability are absent or limited (e.g. change of supplier, etc.) . These modifications must be clearly identified as minor in the application and will be registered as such after approval by the FIA and other power unit manufacturers.”

Finally, point 5.4 lists the incidental modifications allowed for reasons of installation and integration of the power unit in the car. In detail, it is possible to intervene on wiring and intake and exhaust ducts, provided that the fundamental parameters such as diameters and lengths remain unchanged. It is also possible to refine the assembly of the turbo and turbo installation, whose position with respect to the engine, however, can differ by a maximum of 2 cm compared to the previous specification, as well as work on wastegates and pop-off valves, as pointed out by F1 expert Carlo Platella for formulapassion.it.

Then there is another section of the regulation which distinguishes the components that fall within the homologation perimeter and those on which one can work without restrictions. Appendix 3 consists of a table from which we learn that the modifiable components are the following: intake duct upstream of the turbo up to the air filter; intercooler and radiators of the cooling system, including the pipes of the hydraulic circuit; exhaust duct downstream of the turbine; flywheel, clutch and various accessory components.

There is therefore no shortage of opportunities to squeeze a few more horsepower out of the engine, for example by working on the intercooler to best cool the air entering the cylinders. Lower temperatures in the chamber reduce the risk of failures, allowing the turbo pressure to be increased via the MGU-H or the ignition and fuel injection to be calibrated differently to outline a more aggressive combustion. On the other hand, working on the diffuser is essential for working on the rear suspension and on the arrangement of the spring-shock absorber unit. Already in 2022 it was seen how teams with push-rod or pull-rod geometries at the rear also had a different exhaust duct pattern to bypass the internal components.

Finally, when we talk about the development of the power unit, it is appropriate to go beyond absolute power alone, with the competitiveness of an engine that resides in various aspects. The packaging, i.e. the integration of the engine into the chassis, has a great influence on reliability. Working on the housing of the internal components, from the electronics to the cooling circuit, up to the intake and exhaust ducts, is an exercise in compromise with the aerodynamic requirements of the engine cover, as well as for weight distribution and height of the center of gravity. Being able to modify intercoolers and radiators also implies working on internal aerodynamics, therefore on cooling drag, i.e. on the aerodynamic resistance associated with the cooling system, and on the position and extension of the grilles, which influence the external surfaces. In 2022, for example, we saw how the great work by Mercedes on radiators and intercoolers, developed with the aerospace company Reaction Engines, gave life to a streamlined single-seater with minimal side openings.

Finally, in 2023 it will be possible to work freely on the power unit control software aspect, therefore on fuel injection timing, spark plug ignition, turbo speed via the MGU-H, energy flows of the hybrid system and electric motor control. All of this affects torque delivery and driveability, two other central aspects in performance in addition to absolute power, as they determine the possibility of easily discharging driving power and rear tire wear to the ground.

The same aspect is also closely linked to the integration between the chassis and the power unit. Instead, optimizing the energy flows and strategies of the hybrid, with the MGU-H juggling, for example, between recharging the battery, accelerating the turbo and supplying power to the MGU-K, has repercussions on the electrical energy actually available in the lap arc. Hywel Thomas, head of the Mercedes engine department, recently said that in 2022 the Brixworth engineers focused precisely on this aspect, finding marginal gains race after race thanks to deployment strategies, i.e. exploitation of the hybrid, constantly squeezing new fractions of energy.

In conclusion, the development of the power unit will actually be restricted in 2023, but this does not mean that engine manufacturers will not have the opportunity to find precious hundredths of a second, not only through sheer absolute power.