Their respective LMDh prototypes have had their minimum weights reduced by seven kilogrammes for the Bahrain 8 Hours on 4 November under the Hypercar class Balance of Performance.
A change has been made to the so-called ‘platform BoP’, which means the move is an attempt to create a level playing field between the two manufacturers running LMDh machinery and the Le Mans Hypercars from Toyota, Ferrari and Peugeot.
This explains why the weight reduction is the same for both the Porsche and the Cadillac.
New BoP rules for 2023 allowed for a platform change after the Monza and Fuji rounds in July and September respectively.
It follows wholesale revisions for all the cars competing in Hypercar after the Le Mans 24 Hours in June.
This was meant to be the only manufacturer change of the season, but WEC rule makers the FIA and the Automobile Club de l’Ouest opted to override the regulations without the consent of the competitors ahead of Le Mans.
They argued these changes were necessary because the differences in the performance of cars built to the LMH regulations were “greater than initially anticipated” after Toyota largely dominated the opening three rounds of the championship.
A new BoP for the remainder of the season was then published in the run-up to the Monza 6 Hours, though the values were different for the final three races to reflect the specific nature of each circuit.
The Bahrain minimum weight for Porsche’s 963 was set at 1053kg, which has now been reduced to 1046kg.
It raced at 1049kg and 1054kg at Monza and Fuji respectively.
Cadillac’s V-Series was given a 1037kg minimum for Bahrain, now reduced to the class minimum of 1030kg.
The minimums for the American car at Monza and Fuji were 1032kg and 1039kg.
Both the Porsche and the Cadillac will race at Bahrain with a per-stint energy allocation reduced by one megajoule, which reflects the reduction in their minimum weights.
The maximum stint energy for the Porsche is now 908MJ and 894MJ for the Cadillac.
Power outputs of both cars is unchanged from the previous BoP published in July.
Free practice for the Bahrain 8 Hours begins at 12:15pm local time on 2 November.