It's interesting to see Mercedes running a back-to-back of two different nose configurations on the second day of Formula 1 2025's pre-season test in Bahrain.
In 2024, it ran a nose-to-forward-wing element with a slot gap (red ellipse) but for its initial launch nose for 2025 it had a new wing with a slightly different mainplane profile (red highlight) and flap profiles. This configuration also did away with the slot gap.
But a version with a slot gap (green ellipse) combined with the new wing profile and two small slot gap separators (blue ellipses) between the nose and forward element briefly reappeared on Thursday.
I’m a big believer in having the slot gap because I'm also a big believer in airflow consistency. Without the slot gap, you can probably produce a little more front-wing downforce, especially at low speed, and this is something that everyone is chasing.
However, getting the airflow to stay attached to the underside of the nose without a slot gap will not be easy, and that’s the airflow that feeds the central section of the leading edge of the underfloor. That underfloor is the component that produces something like 75% of the car's overall downforce.
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To exaggerate that further, if the slot gap was not necessary for flow consistency and to reduce airflow separation problems then why would you have a multi-element front wing rather than a single element front wing?
The answer is simple - you would be stepping back in technology about 40 years and you would have to reduce the angle of attack so much to eliminate the separation problems on the undersurface that you just couldn’t produce the overall downforce from it.
Yes, it could probably have introduced the new car with the slot gap version and did a quick back-to-back test with a simple cover in that area but Mercedes decided to do it the other way around probably for the reasons I have stated above i.e. more front wing load. Now, having run the car, it may just have identified some inconsistency.
Or it could all simply be that one design or the other is easier to achieve the flexing characteristics it requires...
