The FIA and ACO will implement atmospheric reference pressure adjustments in real-time to GTE cars in the FIA World Endurance Championship beginning next year, in an effort to properly balance turbocharged and normally aspirated engines in all weather conditions.

FIA technical delegate Denis Chevrier has revealed that a new autonomous system is being developed for the production-based categories that will transmit adjustments via the car’s electronics system.

Currently, the WEC declares a set atmospheric pressure on scrutineering day, with daily adjustments having been introduced during last weekend’s Six Hours of Shanghai, for increased accuracy.

“This channel of information will be transferred to the car in real-time,” Chevrier told Sportscar365. “It’s very important for a 24-hour [race], where you can have 5, 6 or 10 millibars different from beginning to end.

“It means during all the event, the atmospheric pressure [for] turbocharged [cars] will be updated to be fair at every single moment of the event.”

The current system came under scrutiny at this year’s 24 Hours of Le Mans, when the declared pressure put the turbocharged Ford GTs and Ferrari 488 GTE cars at a distinct advantage in qualifying, due to it having been predicted for weather conditions for the race only.

Chevrier said it prompted them to introduce the option of making multiple changes over the course of a race weekend, prior to a full, automatic system being put in place for next year.

“We observed that at Le Mans there was a significant change from the qualifying day to the race day, which made it unfair for the normally aspirated engine because we maintained the atmospheric reference pressure higher than data pressure, which means it was not not balanced properly,” he said.

“We need to take care, during an event, if there’s a large difference between the qualifying day and race day.”

The 8-millibar adjustment made between Friday and Saturday in Shanghai, due to a change in weather conditions, triggered outrage from Ferrari, with the Italian manufacturer inaccurately calling it as “Balance of Performance adjustment” in its post-qualifying press release.

ACO technical delegate Thierry Bouvet explained that atmospheric pressure reference adjustments is not categorized as BoP, but rather a compensation for the altitude and weather conditions that impact turbocharged engines differently to normally aspirated powerplants.

“A normally aspirated engine is seeing [the weather changes] as well,” he told Sportscar365. “It’s [undergoing] a live adjustment, so it’s only fair that the turbocharged does the same thing.”

Chevrier said the new real-time system, utilizing the WEC’s at-track weather team from Meteo France, is already being tested and will be rolled out for all turbocharged cars in GTE-Pro and GTE-Am next year.

“It’s not [yet] implemented as a strategy because we want to make sure there are no faults,” he said. “There are some precautions taken on the systems before we implement these things.”