The number is reminiscent of the diffuser dispute from the previous year. One has an idea and the others try to counter it. Without knowing exactly what one is actually doing. Only the result is known: M cLaren breaks the flow at the rear wing at top speed on the straight. The speed measurements at the last test in Barcelona prove: McLaren is on the home straight by at least five km /h faster than the rest of the world. Red Bull bombarded the FIA with inquiries.
Others have also reported to FIA race director Charlie Whiting, but remain under cover as a precaution. McLaren invited Whiting last week to see for themselves the legality of the system. The investigation was postponed to Bahrain.
FIA is not allowed to reveal anything
What exactly McLaren is doing to tear off the current on the wing in order to reduce the air resistance, nobody knows exactly. There are only guesses. The teams try to find answers to the riddle through specific inquiries to the FIA. It usually goes like this: 'Is it legal if we ... do?' The FIA commissioners can only answer yes and no. If a 'no' follows, you at least know that you are on the wrong track with your theory.
Several details on the McLaren MP4-25 arouse the suspicion of the opponents. There's this oddly shaped airbox with an unusually wide top bar, which suggests there's an air duct inside. Air is evidently blown onto the upper rear wing element from said web. But by which method? The element has a fine, curved slot in the lower third. If it does not run across the entire width, that is allowed. Otherwise applies. The upper part of the rear wing may consist of a maximum of two elements. One thing is clear: the slot belongs to the system. Under certain conditions, it lets in more, sometimes less, and sometimes none at all.
Air inlet in front of the cockpit
Then there is a small air inlet diagonally in front of the cockpit, viewed from the driver on the left side whose shape was changed three times during the test drives. TheCompetitors have found out that McLaren used colors on the rear wing to make the flow path visible during a test in Jerez and that measuring instruments were attached to the airlock at the same time. Strangely enough, the paint was only applied to the left side of the wing. Hence the suspicion: one thing has to do with the other.
The question of all questions is: How does the system know if the car is in a fast corner or on a straight? A stall in curves like Eau Rouge or Blanchimont (Spa) would be fatal. A valve could be installed in the airlock that only opens when a certain dynamic pressure is present. But that would be illegal because one could speak of a movable aerodynamic aid. And the valve doesn't know whether the car is driving in a straight line or in a curve. In terms of spa: The back pressure in Eau Rouge or the subsequent Kemmel straight is practically identical.
Control with the knee?
Believe now many that the driver plays the trigger, whether the flow at the rear wing breaks or not. The doubters were particularly fond of that little air scoop in front of the cockpit. Why is it on the left and not in the middle? What is its function? It is definitely not there for cockpit cooling, because the attachment is aerodynamically not optimal. If that were the only reason, then the drivers would have to sweat.
The rivals of McLaren now suspect that the driver is using the knee to trigger whether the air flow in the mysterious rear channel is interrupted will or not. He could bring his left knee into a certain position on the straight that opens or closes a lock.
The driver is not allowed to influence the aerodynamics
But even that would not be compliant with the regulations. The driver must not influence the aerodynamics through primary movements. The situation is somewhat different with the head, which is constantly in motion due to centrifugal forces. Some pilots pull it in on the straight to guarantee a better flow of air to the airbox. This is seen as a secondary movement and would be allowed accordingly.
The McLaren puzzle has not yet been solved. But in Bahrain the spies from the other teams will take a very close look. You can already bet that most of the Lapwing will be around the McLaren on the grid. McLaren cannot cover anything there.