Le Mans prototypes are set for a design tweak aimed at avoiding the aerial accidents suffered by Peugeot earlier this year.
A new rule communicated earlier this month by the Automobile Club de l'Ouest will mandate an opening at the top of each wheel arch, replacing the existing louvers at the front. The cutouts, into which a template measuring 200mm x 250mm (8in.x10in.) must fit, will mean that the top of the wheel will be visible through the hole.
The change is designed to make LMP cars less prone to taking off while going sideways. It follows the introduction of F1-style shark fins at the start of the season as well as a recent increase in ride height.
Nick Carpenter, who pioneered the development of the fins at Delta Motorsport, a British-based engineering consultancy group, explained that the wheel arches would reduce the pressure that could result in a car taking flight.
"If the car goes sideways, the wheel arch scoops up air like a bucket and creates a high pressure area," he told AUTOSPORT. "The air also accelerates over the top of the wheel arch, so you end up with negative pressure on top. That's why a hole is a good thing."
Audi Sport technology chief Martin Muhlmeier raised doubts about the move, however.
"This is certainly the right idea in theory, but these openings reduce the vehicle's stability on the straight, because its center of gravity shifts forward," he said.
The rule change will only lead to slight reductions and increases in downforce and drag, respectively, according to OAK Racing boss Francis Sicard, who told AUTOSPORT his team had already regained some of the losses during its first wind tunnel tests with the openings.
Teams will be able to defer making the changes until April 1, but will have to run with as-yet unspecified weight penalties if they choose to do so.