Article in Endurance-Info
"Following the 2013 24 hours, the Endurance Committee has been solicited by the GTE brands to homologate a "kit Le Mans calibrated by a BOP" in order to take into account the specificity of this race which requires less drag. This new kit was supposed to be used at Daytona, but is wasn't finally.
The Endurance Committee believe it is necessary to organise aerodynamics tests at
Ladoux, on the Michelin track, with one car of each brand engaged in GTE-Pro.
At the end of these tests, an adjustment will be decided before Le Mans. Without these measures, it won't be possible to use any aero specific kit for LM. The cars will be controlled with the specific equipment (
at the pesage I assume). The legislator is keen to ensure that the LM GTE will stay in the range of set-up defined during these tests."
I hope this quick translation is OK.