How McLaren’s F1 hopes rest on a game of millimetres

The team was open, ever since it first revealed its 2023 challenger, that the launch specification was not where it wanted to be, and that a new development path was needed.

The first fruits of that labour appeared at the Azerbaijan Grand Prix, as McLaren introduced a revised floor that had some very alternative treatments around the edges.

The fact that the McLaren updates appear visually not too different, but have a big impact on the way airflow is managed throughout the car, highlights a fascinating aspect about the current generation of ground effect machinery: the smallest details count for a lot.

McLaren team principal Andrea Stella, who comes with vast experience as an engineer, says that floor designs are critical to current car performance – but much of the effort to improve them involves tweaks that can’t be seen, or adjustments that are so tiny they are almost impossible to spot.

“With this generation of cars, a lot of what's contributing to the performance is what you don't see, it's under the car,” he explained.

“This is very different from the previous generation of cars where the geometry was prescribed as being flat. Now there's no prescription.

“So, if you look underneath, you'll see channels, which play quite a significant role, and fences which all play together.

“You have to get the basic concepts right, which is something we haven't done for the start to the season, but it's also starts to become a game of millimetres here and there.

“They make the difference for how stable vortices are when they travel. And also, it makes a difference for porpoising.

“The name of the game now, in terms of getting the flow right, is understanding what is the high-level concepts that you need to focus the development on. And then it's a real game of millimetres, with many, many iterations in many areas of the car and the floor by many people in the aerodynamic room.”

Lando Norris, McLaren MCL60

Photo by: Steven Tee / Motorsport Images

The fact that tiny changes can have a big impact on how the air stream interacts with the rest of the car means the planning for upgrades has had to evolve as well.

Whereas in the past, teams may have put a lot of effort on big ticket items, like new front and rear wings, or bargeboards, to deliver a guaranteed downforce boost, now teams have to spend more time understanding the detailed implications of every tiny change.

Revisions can no longer be made is isolation, as one small tweak to an element at the front of the floor can then cascade to requiring further refinements all the way through to the back of the diffuser.

“If you change the fences, then you need to adapt something else,” added Stella. “Everything is connected three dimensional. It's difficult to find a detail that works in isolation.

“It was much easier with the previous generation of cars, where you had modularity in terms of building the floors, and also you could just take the forward floor and rework it at the factory.

“With this one it's difficult to do that, and it doesn't work aerodynamically. So there's a bit more of a challenge from this point of view in terms of development rate.”

But while it may be harder for teams to evolve and improve their cars, one factor is proving to be easier to deal with – and it is that there seems to be better correlation between what the factory says the car should be doing and what really happens on track. Stella says the older generation of cars were much harder to predict.

“I think this generation of cars is overall better correlated, at least at McLaren,” he said.

“Having the limitations of the wind tunnel with the previous generation of cars was very restrictive, not only for the logistics, but for the aerodynamic correlation genuinely.

“With these cars a lot happens on the floor, where overall the correlation is better for whatever reason. In the previous generation, there were many vortices that were flying in free air and generated from the side, from the bargeboards for instance. So that area was always a little more tricky for the front wing.

“But this [2023] front wing works farther away from the ground. It's simpler. Even the floor for some reason correlates better. So overall, I think it's more to do with the generation of cars.”