They revealed their intent to revise the BoP for the double-points round of the World Endurance Championship to the manufacturers on Wednesday, Autosport has learned, just four days before the cars are due on track for the Le Mans Test Day on Sunday.

The changes were presented by the FIA and the ACO as done deal and there was no attempt to gain the unanimous agreement that in theory was necessary to make revisions outside the prescriptions of a new Hypercar system introduced for 2023.

As the ultimate arbiters of the series through a body known as the WEC Committee, the FIA and the ACO have exercised their right to make unilateral changes to the BoP.

This was tacitly acknowledged in a joint statement from the FIA and ACO released on Thursday morning, which described the new BoP table for Le Mans on 10/11 June as a “correction”.

It explained that it was necessary because the differences in the performance of cars built to the Le Mans Hypercar rules were “greater than initially anticipated”.

All seven participating marques in Hypercar were signatories to the new system, which was devised to prevent manufacturers hiding their true performance or sandbagging to gain a favourable BoP.

The BoP was set in stone for the first four races of the WEC up to and including Le Mans, with only a change in the balance between LMH and LMDh machinery, the so-called platform BoP, permissible in that period.

There was confusion over when this could take place under the agreement, which remains outside the public domain, but it was made clear that changes to the BoP for individual cars built to the two different rulesets in operation in Hypercar was only possible after Le Mans.

It is understood that the ACO president Pierre Fillon and Richard Mille, who is boss of the FIA’s Endurance Commission, drove the decision to make changes beyond the scope of the latest BoP guidelines ahead of the centenary edition of Le Mans.

#7 Toyota Gazoo Racing Toyota GR010 - Hybrid: Mike Conway, Kamui Kobayashi, Jose Maria Lopez

Photo by: JEP / Motorsport Images

Toyota received the biggest hit under the BoP with a 36kg increase in minimum weight for its GR010 HYBRID LMH, which won the opening three rounds of the 2023 WEC.

The Ferrari 499P LMH will run 24kg heavier than previously, while the Cadillac V-Series.R and Porsche 963 LMDhs have received 11kg and 3kg respectively.

An unchanged BoP is in force for the Peugeot 9X8 LMH, the Glickenhaus-Pipo 007 and Vanwall-Gibson Vandervell 680 non-hybrid LMHs.

The only comment so far from one of the Hypercar manufacturers has been a tweet from Toyota driver and team principal Kamui Kobayashi.

He wrote: “The addition of 36kg is worth a 1.2s a lap loss. It's a really, really painful change. But we have no choice but to win - that's the only proof that we have made a good car.

“To all the engineers, I'm sorry for our lack of power. But even in this tough situation, let's make a good car and win!"

The full text of the FIA/ACO statement reads: “The first few races of the 2023 FIA WEC season have shown differences between different LMH-spec cars competing in the Hypercar class to be greater than initially anticipated,”

“Considering these factors, and following an in-depth analysis of available data, the WEC Committee has decided that the goal of ensuring a level playing field within the Hypercar class will be best achieved by implementing correction between, but also within, the LMH and the LMDh platforms.”

2023-06-01T09:34:54Z dg43tfdfdgfd