Further info regarding the tests results after the first 5 races and about the Miami upgrades:
1.
What they found after the tests:
- The first five races of the season have confirmed that both the drivers and engineers are still dealing with a difficult car that works intermittently and often is peaky and when it does it's not entirely clear why.
- If there is one thing that became crystal clear for Mercedes in Shanghai is the fact that the W15 has no more performance to offer and basically is a weak car.
- They have learned the biggest concern of the W15 is not having solved the lack of stability which is exactly the main deficit of its ground effect predecessors.
- The car is able to generate loads of downforce but only in a very bleak operating window which makes all that downforce unusable breaking down the car's marginal setup window in return making the W15 unpredictable at most in instances.
- The new rear suspension was a solution that the team hoped would widen the car's operating window. However, from the enormous number of tests carried out by the team till now, the platform Mercedes has designed for 2024 still moves a lot and Jeddah proved the most crucial of details as the tests carried out in Saudi Arabia revealed that the car still tends to bounce around corners very much unsettling the car.
- Examining across performances the car has lost its edge on better tire degradation as the W15 has become sort of a butter shredder.
2.
What the Miami upgrades are trying to solve:
- As a general observation, the upgrades to the W15 could now be done more easily compared to prior seasons considering that the W15 does not restrict the Brackley technicians in terms of gearbox chassis or suspension structure
- The new components aim to stabilize the car to decrease the floor sensitivity and recover mechanical grip by introducing a new underfloor alongside making changes to its central and side bodywork
- Last year the team made the needed ramifications for the W15, Mercedes now has the wiggle room to introduce aerodynamic upgrades to try and manipulate the car's platform and aerodynamic balance.
- Mercedes introduced its first upgrades in Japan in the form of a front wing revision which went unnoticed by many, the next fine improvement was made in China in the form of an aerodynamic flick behind the Halo to generate vortices improving the car's rear end airflow
- For Miami, the team will introduce aerodynamic parts surrounding the car's underfloor revising the floor's top bottom, and edges to revise the load distribution around the underfloor moving more load towards the car's rear, the work around the floor's aerodynamic seal is to decrease the bottom sensitivity thus improving stability and mechanical grip.
- The floor upgrade also will aid in improving the W15's ability to extract more performance out of its tires significantly improving tire degradation
- The w15 will have revised radiator inlets that give an increased undercut region of the side pods to utilize pressure differences to improve airflow towards the rear of the car.
- Overall these upgrades at Miami are particularly aimed at enhancing the W15's aero-mechanical interaction which has been lacking and stabilizing the aerodynamic performance of the W15 at various speed ranges, especially to the low to mid-corner speeds.
- This upgrade package is believed to produce 2/10 worth of lap time gain but more importantly, the package is aimed at a crucial aspect if we to believe the statements coming out from Brackley the team's priority within this upgrade is to verify the proper correlation between the virtual world and the racetrack:
- The Silver Arrows also hope these upgrades do add performance stability for the most part James Allison revealed
in the team's latest post-race debrief video adding:
- The Brackley-based squad's game plan for 2024 was very much similar to that of Ferraris build a solid foundation first then work on adding performance but since Bahrain, it's been evident that the so-called solid foundation has not been established.
- Within ground effect regulations the most effective medium to have a stable well-balanced car is to generate as much downforce as possible through the floor to strengthen the rear of the car while it is simple to say this achieving set performance through the floor is a complex task. This is because the floor is subject to interference during yaw and pitch movements affecting the floor stability. It is therefore a question of stabilizing the aerodynamic platform as much as possible to decrease the floor sensitivity to interferences and offer the correct vertical thrust in all speed ranges of the car. Mercedes with its Miami upgrades are trying to do this exact thing coupled with the W15's improved mechanical platform thanks to the revised suspension and chassis layout.
- While one hiccup the team could potentially face at Miami will be correlation issues between CFD, WT, and on-track performances one big concern will be the Sprint format bestowed upon the race weekend. Following the exploratory attempts during the Chinese Sprint Mercedes is certainly going to revise their tactics for this race weekend confirmed by James Allison himself :
...
Now my thoughts about the W15 after the five races:
- The engine wants cold weather and the tires want warm weather.
- The car is fast in a straight line when the engine is cranked up and when the ambient is cold, but lacks mechanical grip.
- When it’s hot the car is slow in the straights but has more mechanical grip. The W13 car had more downforce from the new floor late in the year than the W14 car, but the W15 suspension is better than the W13. So, they sacrificed some downforce for better suspension stability and adjustment, but this led to sacrificing the tire warm-up since the suspension is so gentle on the tires now.
- The anti-dive front suspension is too rigid for this ground effect car era making the car understeer more and adding to the lack of tyre warm-up, particularly the fronts.
recency bias is crazy