Renault, or Alpine as we now have to call it, has never really had what I would call a slimline airbox/engine cover but I think the version on the A521 is taking it to the extreme.
It reminds me of the Ligier JS5 of Jacques Laffite from 1976, amid F1’s trend of tall airboxes outlawed after four races of that season.
Other than covering up what’s under that section of the bodywork, and/or allowing some of the hot air from the radiators through that section of the body, allowing it to keep the body tighter lower down in the Coke bottle area, I can see no practical or aerodynamic reason for this very bulbous solution.
The difficulty in this area is to get the airflow to stay attached to the body surfaces as it comes off the driver’s helmet, which is moving around quite a lot. Also, when the driver opens or shuts the throttle, the airflow will change.
If any of this causes separation, it can affect the rear wing performance.
There are much more elegant solutions out there.
