Although Lando Norris’ triumph was not won entirely on pace, as Max Verstappen’s RB20 was damaged after he ran over that bollard, it was clear that McLaren’s upgraded MCL38 is now a serious challenger.
What’s most important to understand, though, is that its success is not just the result of the single upgrade package brought to Miami.
Instead, it has been a carefully plotted plan that can be traced back all the way to before the 2023 MCL60 had even turned a wheel in anger because the team knew it was not good enough.
This approach meant something of a leap of faith, as it brought only minor performance updates in the opening races of last season while it worked on the major overhaul it knew it needed.
What arrived at the 2023 Austrian Grand Prix was substantial, with Norris the first to sample what was akin to a B-Spec machine.
The transformative Red Bull Ring changes
The package installed on Norris’ MCL60 was completely transformative, not only in terms of looks but also in lap time, as the team immediately leapfrogged its way towards the front of the pack in a manner that’s very unusual in modern F1.
The focal point of the update package was on the sidepod arrangement, with more of an underbite created, as the lower lip of the inlet was raised and brought forward [2]. This resulted in a much more generous undercut, providing passage for the airflow to the rear of the car.
Meanwhile, the mirror assembly was adjusted [3] to alter the flow conditions on the sidepod’s upper surface which had also been fettled, with the shape of the rear ramp altered and a deep-water slide gulley also added [7].
In restructuring the aerodynamic surfaces, McLaren also altered its radiators and cooling, which also led to the engine cover and cooling outlets being redesigned.
The larger panel of vertical louvres on the side of the engine cover [9] were replaced with a longer panel in a more rearward position and featured much shallower louvres [8].
To supplement this, an additional outlet was added around the lead arm of the upper rear suspension wishbone [11].
There were also changes to the floor’s body, floor fences and edge wing, all of which are critical in finding performance under these regulations and must work in conjunction with the surfaces around them.
Leading the way at Silverstone
The update package was further complemented at the following race, when McLaren had enough parts at its disposal for both drivers to have the upgrade, as well as a new front wing.
The team, like many others on the grid, had adopted a semi-detached flap and endplate arrangement, resulting in more outwash potential. The discontinuity of the surfaces alters the vortex that is formed and pushes the airflow across and around the tyre's face.
McLaren also made a subtle change to the profile of the nose at Silverstone, with the bridge flattened out to complement the changes made to the surrounding front wing elements.
This all added up to a package that allowed Norris to briefly lead the British GP and eventually come home second.
Keeping up the development push
The team's progress did not stop here, as it began to add different rear wing tip section designs into its suite of options, which presented more flexibility in finding the right downforce and drag levels at each venue.
This included some tricks seen elsewhere on the grid, with the team trying an infill panel, which was first seen from Alpine but was more widely used by Mercedes thereafter.
It also introduced two different versions of the semi-detached tip section too, with a more rolled iteration used on its higher downforce wing solution, while a broader version was employed on its lower downforce variant.
Another significant waypoint in the MCL60’s development cycle came at the Singapore Grand Prix, as the team made further refinements to the front wing, floor and sidepods.
This included a change to the camber of the front wing endplate, altering how it interacts with both the diveplane and the semi-detached flap arrangement it had opted for at Silverstone.
The floor and edge wing were also amended, as the team removed the cutout that had been part of the revamps in Melbourne and Baku and returned to a longer edge wing but now with a tapered tail to complement the floor’s edge.
Changing approach in 2024
The earlier adoption of the underbite sidepod arrangement, albeit not as aggressively in lockstep with the lengths that Red Bull went to in 2023, appeared to set the team in good stead, with many others set to also join those ranks as the majority of the field moved to an underbite solution.
However, when the MCL38 was unveiled it became clear that McLaren had bucked the trend and readjusted its aim – something that later seemed validated by Red Bull’s own total overhaul and move to an overbite solution.
In both cases, it seems the teams found the natural ceiling for the underbite solution.
While in isolation it likely provided more performance from both an aerodynamic and cooling perspective, that window narrowed over the course of time when taking into consideration what performance could be exploited both up and downstream of the inlet arrangement.
The Miami changes
This additional overhead has resulted in the changes seen on the MCL38 in Miami, as the new inlet arrangement is not only wider but also shallower than its predecessor.
In-turn, this has increased the size of the undercut and allowed the team to widen the sidepod’s bodywork and alter the shape of its flank to improve the overall flow conditions.
Additionally, the deep gulley that had been a prerequisite of the changes made during 2023 has been tamed.
There is a flatter surface formed on the upper portion of the sidepod bodywork, while the gulley now only starts to form as the surface descends more abruptly down into the coke bottle region.
McLaren was unable to furnish both of its drivers with all of the updates in Miami though, with Oscar Piastri having to wait until Imola to get the full roster of parts, as the sidepod’s also had to undergo a transformation beneath the skin too.
To complement these changes, amendments were also made to the engine cover bodywork and cooling louvre arrangement.
Some shots of the MCL38, as it was craned away from the scene of Norris’ exit from the sprint, also confirmed that McLaren’s underfloor has a couple of features from its rivals’ machines in order to enhance the airflow’s behaviour.
A row of mini strakes, a feature we first saw on the Mercedes W14, can be found on the underside of the edge wing, to help break up and repurpose the airflow as it makes its way around the structure.
Meanwhile, a wedge-shaped section of the diffuser’s roof has also been created, similar to what we saw from Red Bull last season, which trades space within the diffuser with the floor’s upper surface.
Piastri’s pace throughout the race weekend suggests that other parts in the update, of which he also had access to, were providing a sizable advantage, with a new specification of front wing one such component to have been fitted to both cars.
The biggest change here is the shape of the mainplane (red arrows), with a wider central section that will alter the behaviour of the flow stream aft of it, resulting in some subtle changes to the inboard elements to maximise its yield.
Changes were also made to the suspension fairings and brake ducts, both front and rear, in an effort to realign the airflow and take advantage of the other changes being made, which for both cars included a new, more offloaded single element beam wing.
Keeping going
McLaren is clearly on the right track, having turned around a car that was considerably off the pace just 12 months ago.
However, like last season, it will need to continue to develop these concepts over the remainder of the campaign, as its rivals are also expected to deliver significant update packages of their own over the next few races.
And, as we all know, if you stand still in F1, you go backwards quickly.
