https://the-race.com/formula-1/where-performance-gains-can-be-made-despite-f1s-engine-freeze/
"...Alpine executive director Bruno Famin, head of the engine base in Viry-Chatillon in France that produces the Renault power unit, explains, while you cannot directly improve the performance there are “very small margins” where packaging can be improved.
The nine frozen parts of the power unit and related items are the V6 engine, turbocharger, MGU-H, MGU-K, energy store, control electronics, exhaust system, fuel and engine oil, with the deadlines for the final specification kicking in variously in March and September last year. That means these cannot change for the remainder of the current rules cycle, which runs to the end of 2025.
“There is no real margin to be honest because, by rule, you cannot improve the performance of the engine,” said Famin when asked how much margin there is for improving the power unit.
“What we can do is try to improve the performance of the car, and the possibility we still have as per the regulation is the packaging.
“This is where we are working. We’re working of focus in the use of the energy management, but here again we are going to be
very limited as we’re going to have only one software version per year now. We are pushing like that, but it’s more on the on the drivability.
“We are going through the ideas to progress, which is very small margins. It’s not pure performance, it’s more drivability and integration/aero gains.”
The regulations also allow for what are called “minimal incidental changes” to be made, but these are tightly controlled and only apply to seven areas. This is defined as “for car installation purposes”.
These apply to wirings, the exhaust system (“provided the key defining parameters remain fundamentally unchanged”, the turbo-compressor position (“within 20mm from the original position relative to the ICE”) as well as turbo clocking and turbo supports, the position of wastegates with housings and pipes, the position of the pop-off valves housing and pipes and minor details of the air inlet system.
While none of these make a massive difference, they can be used to make tiny tweaks to the packaging of the power unit for potential marginal performance gains...."
