McLaren’s MCL35M was the first car to be unveiled ahead of the 2021 Formula 1 season and given it shares the same name as last year’s car, it came as no surprise that it looked almost identical.
Whilst it is difficult to notice the substantial changes, casting a technical eye over the car compared to last year’s you’ll see plenty of development has taken place, likely more so than on any other 2021 car.
Even then, the majority of changes won’t really been seen until pre-season testing when further parts are bolted on. There still a month’s worth of development time between the launch and the first day of testing, scheduled for Bahrain on March 12.
But the McLaren will undergo some of the most visible changes because of a non-visible change – the switch from Renault to Mercedes power. The engine change has not only completely changed the mechanics under the bodywork, but thanks to some exemptions by the FIA, McLaren has been able to adapt the parts approved in 2020, such as the chassis, gearbox, suspension attachments and cooling, to accommodate its new Power Unit (PU).
The first difference you might notice, albeit minimal, is the more sculpted sidepod/engine cover, which is a direct result of the new PU.
The team has been able to conform its bodywork to fit the new PU, which has a completely different layout to that of the Renault PU. The sides are more tapered than last year, whilst the McLaren-made gearbox has undergone some changes to accommodate the new PU.
The bodywork, which narrows just behind the drivers compartment, recreates that famous aerodynamic slide that brings the flow of air to the floor and diffuser, just like on last year’s Mercedes. It is also possible to observe the new floor, free from slots and channels for the air flow, which follows the updated technical regulations.,
This looks to be a ‘launch-spec’ floor and is fairly primitive in design, so we can expect to see a lot of changes in this area by the first race of the season as teams look to recover the downforce lost as a result of the rule change.
As for the air intake above the driver’s head, you can see the shape has changed and is now more similar to that of the Mercedes W11.
An interesting technical detail is represented by the air intakes for cooling on the sides of the driver compartment, which have wider and more sloping vents than the MCL35, following the trend to descend towards the bottom of the new bodywork of the sides. It is clear that the management of the cooling between the Renault PU and Mercedes PU is quite different, and required considerable work over the winter for the James Key and his engineers.
One of the most visible changes you might not notice, unless compared side-by-side to the 2020 car, is the longer wheelbase of the MCL35M. Also the increase in pitch could be a direct consequence of the implementation of the Mercedes PU – which also runs a longer wheelbase – but which also involves an increase in the efficiency of the diffuser.
The aerodynamic restrictions at the floor and diffuser have also led to a decrease in the rake set-up, as we will probably see on the other cars that will be presented in the following weeks. The high rake set-up, which is something championed by Red Bull, is more penalising with the changes made to the new technical regulations.
In 2021 the Pirelli tyres will also change, which will have a more rounded shoulder and a more rigid construction to be more resistant to the stresses due to the increase in downforce. In this regard, while not being able to modify the internal homologated parts of the front suspension, McLaren has slightly revised the design of the pivot of the upper triangle (green arrow) and of the bracket, that is the element that moves the anchor point of the suspension strut to a push rod scheme. They have also revised the brake duct, which has a wider shape in the upper part, forming a sort of “inverted L”.
In terms of aerodynamics, the first real innovations studied by James Key and his colleagues will certainly be seen on their debut in the pre-season tests. The MCL35M seen in the presentation still featured much of the aerodynamic components present on last year’s car.
However, some differences with the MCL35 have been seen, especially on the rear-wing endplate, of which we have seen the twisted slots like on the Haas VF-20 and Red Bull RB16, and not straight like in the old solution of last year. Also, in the rear-wing area, remains the double-profile T-wing seen last year in the high-power circuits.
Analysing the aerodynamics at the front, it can be seen that the barge boards are very similar to the latest development last year, but have simplifications that were dictated by the 2021 technical regulations, which resulted in the abolition of the double boomerang. In fact, the new flow diverters, although always very complex in design, are simplified.
The nose is also almost identical to that of last year, and maintains the same front impact structure approved at last season’s Tuscan GP. The mantle flow diverter, called “cape”, has been slightly revised, which compared to the late 2020 version is more aligned with the turning vanes under the frame. While maintaining the same deformable front structure, McLaren has continued to develop the aerodynamic part that surrounds it, to have a greater cleanliness of the flows under the car.