Bill Brewer, Jan Stewer, Peter Gurney, Peter Day and Daniel Whiddon write:
Since the Australian Grand Prix there has been speculation over teams using So-called flexible floors to achieve some sort of aerodynamic advantage, notably Ferrari and BMW.
It is alleged that some teams are using devices such as springs, flexible struts or wire to allow the front of the floor, usually referred to as the front splitter or front floor to rise up under high speeds. What this achieves is a significant disruption of the air flow under the car resulting in a partial stalling of the floor and diffusers suction effect.
Most people will recognise the front and rear wings and other exterior aero devices, such as barge boards, flick ups and winglets etc. What they won't realise is that the floor and rear diffuser form what is actually the largest wing assembly on an F1 car and also the least visible. Whereas the exterior wings assembly's create down force at speed, the floor and diffuser create enormous suction, pulling the car down on its tyres and improving traction and grip tremendously.
As with all aerodynamic devices there is the inevitable penalty to be paid in the form of drag and this is where a flexible floor gives the advantage. At the highest speeds down the straights, the car does not require down force at the same intensity as when negotiating corners and chicanes. But it is at these same highest speeds that it generates its highest levels of both down force, floor suction and drag. By reducing suction created by the floor, you reduce drag and thereby gain an advantage that is two fold. Maximum straight-line speed combined with high down force levels in the twisty bits
The floor and diffuser, like all aerodynamic devices fitted to the cars are restricted by certain parameters in the FIA rules which must be adhered to for the car to remain legal and this includes movement under load. Static load tests applied by the FIA in scrutineering are often not sufficient to detect deflection in aerodynamic devices as the devices themselves often rely on dynamic loads (movement) to function (and this is how they are designed to work!).
All these rule challenging, flexible, aero devices rely on clever design and interpretation of the rules with some teams being more effective at it than others. It's usually the teams which have the least problems with their cars aerodynamically that have the time and opportunity to get more adventurous. It also requires an exceedingly good knowledge of the cars aerodynamics and how they function in order to use such devices without compromising the car totally.
In addition to this the cars composite designers must be good enough to design car parts which can achieve functional reliability as well as the aerodynamic characteristics as tested in the tunnel. We have all seen examples of where its gone wrong, although many TV viewers probably won't have realised. Without naming names, think how many teams in recent years have lost rear wings, barge boards and front wing parts and attributed it later to a manufacturing fault or similar. What you have been itnessing is those teams finding the limits of their flexible bodywork.
It's unlikely that we will see any floors failing this year, but undoubtedly the FIA will be looking more closely in the successive races, although it would be unlikely that they will prohibit or eliminate the use of the so called flexible floors. Generally they will only take strong action if there is a real risk to safety or an unacceptable competitive advantage. Being realistic about it, if neither of these things is apparent then let the other teams react by using their own solutions and rise to the challenge.
All teams and the FIA know that every single competing car will not be legal in some respect relating to aerodynamics and that it is a fact of racing life. With all teams exhibiting this to some extent it cannot really be seen to be anything other than innovative competition between the design teams and aerodynamicists against each other and against the FIA.
