The underbody of a car works very closely with the front wing and splitter (feeds the air to underbody) in the front of the car and diffuser (extracts the air from under the car) on the back. This generates about 35% of the cars entire downforce.
It did not escape the eyes of Charlie Whiting's men in Australia that the cars of the top teams had a somewhat exaggerated rake angle: that is, when the car was in motion the front wing was visibly lower, similar to an abutment structure, with a lower front and visible higher rear. An abutment structure is a structure that supports the lateral pressure of an arch, similar to the at the ends of a bridge. The splitter in this case, with high pressure underneath becomes an abutment structure to support the lateral pressure of the car above it.
|Comparison of rake angle in 2011 cars|
The extra flexing of the splitter helps protect the wooden plank under the car that prevents bottoming out when the rake angle of the car is too high. This is possible because the splitter in the underbody, the lowest point of the car, deflects upward, avoiding the wooden plank from crawling on the asphalt of the track and wearing out more than allowed in the regulations (they are granted 2 mm of wear) which will lead to their disqualification. Charlie Whiting and Jo Bauer over time have changed their method of inspection to keep an eye on the deflection of the splitter, just to avoid the rake angle being exaggerated to gain an unfair advantage.
|Comaprison of rake in 2013 cars|
We can also therefore draw the inference that it is no coincidence that the top four cars that finished the race were using illegal devices on their car, while the third team won at the Australian Grand Prix with the same device.