In Free Practice for the Spanish this weekend, Ferrari caused a small technical controversy when they ran a new rear wing. This new wing appeared to have large extension to the rear flap. After the days sessions were complete Charlie Whiting from the FIA spoke to Ferrari about its legality.
We can see the wings long extension is not in fact a gurney flap as it is not an “L” shape. Instead the extension forms a continuation of the flaps shape. This makes the wing some 30mm longer than allowed within normal interpretations of the regulations. Clearly this much additional surface area will create more downforce. Beneficially this tall extension also retains the DRS pivot axis in its normal location, such that the when the larger flap is moved by the DRS the flap flattens out much more than with a conventional large flap (See https://scarbsf1.wordpress.com/2011/05/20/drs-optical-illusion-why-some-wings-appear-to-open-wider/).
How could this be achieved legally?
3.10.3 In order to ensure that the individual profiles and the relationship between these two sections can only
change whilst the car is in motion in accordance with Article 3.18, they must be bridged by means of pairs
of rigid impervious supports arranged such that no part of the trailing edge of the forward section may be
more than 200mm laterally from a pair of supports. These pairs of supports must :
– be located no more than 355mm from the car centre line ;
– fully enclose each complete sections such that their inner profiles match that of each section. With
the exception of minimal local changes where the two sections are adjacent to each other, their
outer profiles must be offset from the inner profiles by between 8mm and 30mm and may not
incorporate any radius smaller than 10mm (‘gurney’ type trim tabs may however be fitted between
the supports) ;
– be aligned as a pair so as to provide a bearing across their full thickness and along a profile length
of at least 10mm when the distance between the two sections is at its closest position ;
– not be recessed into the wing profiles (where a recess is defined as a reduction in section at a rate
greater than 45° with respect to a lateral axis) ;
– be arranged so that any curvature occurs only in a horizontal plane ;
– be between 2mm and 5mm thick ;
– be rigidly fixed to their respective sections ;
– be constructed from a material with modulus greater than 50GPa.
What I believe Ferrari have done is the sandwich the two separators together in the centre of the wing, then split them at the “V” cut out in the middle of the wings trailing edge. Each separator then runs along the trailing edge of the flap, creating the extension. As the extensions can be 30mm deep they can be 10mm more than the 20mm allowed for Gurneys.
It could beat the rules as each separator runs along the trailing edge, no part of the wing is 200mm laterally from a support. The change from the longitudinal centre separator to the trailing edge could meet the horizontal curvature requirements.
Overnight I heard from Spain is that the wing will be allowed for this race, but a clarification from the FIA ill ban this interpretation for future races. However this morning conflicting stories are emerging. Andrew Benson from the BBC reports “Ferrari have been told they cannot run their “clever” new rear wing design – it exploited a loophole in the regs to do with overall height” (@andrewbensonf1).