McLaren has put the squeeze on for Baku with its narrower bodywork at the rear of the sidepods on its MCL35M Formula 1 car.
Though F1 is doing back-to-back events on street circuits, in contrast to Monaco Baku has long straights – and even some very long straights – so cooling is not as much of an issue as it was in Monte Carlo two weeks ago.
But this change to the rear of the engine cover bodywork section where it narrows is not all about cutting back on the cooling, it’s mainly about improving the airflow over the top of the floor and onto the top surface of the diffuser.
The double-ended green arrow is the area that you want to make as big as possible. But there are lots of things inside that need to be housed and the outer surface needs to offer a surface that the airflow can stay attached to.
That’s what all the flow-viz is about – just making sure that the flow is consistent and is going where you want it to go.
The red lines are where the airflow comes off the trailing edge of the bargeboards and around the undercut sidepod area and heads inside the rear tyres and over the top of the diffuser surface.
The yellow lines are where the airflow would be pulled off the top surface by the low pressure underneath the car.
Having more opening for the red airflow means that the rear brake ducts – which again for this year have been reduced in width – can pull that blue airflow up and inside the rear tyre. This reduces the yellow flow going into the low pressure underneath the car.
These ducts have very little to do with cooling the rear brakes. Basically, they are a collection of small horizontal wing-shaped turning vanes pulling the airflow that would detract from the performance of the underfloor and diffuser up and inside the rear tyres.
These changes may be as a result of the introduction of the Z-floor in Spain, or as a result of being able to react to the cooling requirement of the Mercedes power unit.
Either way, it is more about improving the airflow on the upper surface of the floor and diffuser.
