McLaren MCL35M will be the only car on Formula 1 grid with different power unit, thus the least related to its 2020 predecessor. The addition of the “M” by the name MCL35 is to acknowledge the recreation of the former very successful partnership between McLaren and Mercedes.
With Formula 1 being affected by global pandemic and financial constraints, new rules only for 2021 season were set to restrict the development of the new monocoque. Formula 1 teams must race the same homologated chassis from 2020 season, the development is allowed only for the outer bodywork of their cars. The development token system is in place to control an all-out development race for 2021, and McLaren is the only team to spend their available tokens on accommodating new power unit. That’s why it is general believe that this car will differ the most from it’s predecessor, the others will have easier task to refine their existing packages using available tokens.
With MCL35M being largely new car under the skin due to the Mercedes power unit, there are visually other subtle changes affected by this and the new rules regarding the floor surface in front of the rear wheels.
The front of the car is carried from last years MCL35, so on this early days the front wing and nose are the same as last years late developments.
The roll hoop and airbox behind the driver are reshaped and reconfigurated for the new power unit requirements.
Sidepods are also reshaped and even more tightly packed with bulge along the surface, somewhere in the middle of the engine and gearbox packaging.
Mercedes power unit has a different general architecture compared to last years Renault unit, with compressor separated from the turbine and placed in front of the engine block. This triggers change on the length of wheelbase, rear axle is moved a shade rearwards. This will have big impact on cars dynamics and rear packaging.
The other visible change that will affect all the other cars on Formula 1 grid is the diagonal cutout on the floor surface in front of the rear wheels, and banning all the slots, holes or fins along the floor surface in that area, which in the past have conditioned the airflow. It is new rule (restriction) to cut the downforce levels of the car so that Pirelli can carry with the same tyres as previous years. The downforce levels have increased much in the last years and the aero load generated from the car became huge burden on the tyres.
James Key, McLaren technical director:
“Despite a relatively stable technical regulation from 2020, there are several important aerodynamic changes to the rules and it was important to do it right.”
“Every change to these regulations presents an opportunity, and the Woking team has worked incredibly hard in difficult conditions to maximise these opportunities.”
“One of the key elements in the design of the MCL35M is the integration of the Mercedes-AMG powertrain, which required a considerable effort from the Woking team, as well as our colleagues at Mercedes.”
The McLaren MCL35m right after presentation made smooth track debut at Silverstone as a small preparation for the official winter testing at Bahrain.
Link from Formula1.com video of the first outing on track for McLaren MCL35M.