What is BoP at Le Mans 24hr
Saturday, June 08, 2024
BoP is a key element of Hypercar and LMGT3 regulations. It is a series of technical adjustments, primarily affecting weight and power, that are designed to create a level playing field among cars of different design and architecture. Here's a comprehensive explainer of the process as we are only a week away from this year's 24 Hours of Le Mans.
BoP therefore maintains a similar level of performance between all cars, which reduces development costs significantly. All the manufacturers present on the grid accepted the underlying principles before entering the FIA World Endurance Championship (WEC) and the 24 Hours of Le Mans. BoP has therefore played an active part in producing grids of unprecedented strength and depth, with 14 manufacturers represented in 2024.
The purpose of BoP is to balance the cars’ performance potential. In other words, it assumes that each car is exploited to the hilt. It is not designed to erase performance deltas between two cars built by the same manufacturer or to help an abnormally slow competitor make up the entire gap on their rivals. Nor does it replace operational performance – whether that be tyre management, driver ability, pit time or racing performance – which are all decisive factors and the major component of overall performance.
How does Balance of Performance work?
BoP is established jointly by the FIA and the ACO, who work closely with the various manufacturers. It draws on the data measured during the cars’ homologation process and, as far as the FIA WEC is concerned, on each manufacturer's individual performance recorded on the racetrack by means of various sensors and indicators.
For Hypercar, it is defined in three successive steps. Firstly, the FIA and the ACO balance the “homologation parameters” – the technical characteristics observed during homologation when the cars are inspected, measured and examined in a wind tunnel. It should be remembered that the aerodynamic performance window applying to Hypercar homologation is very narrow, so there is very little difference between the cars before reaching this first step.
The second step is “platform equivalence”. Two different technical rulebooks govern the Hypercar class: Le Mans Daytona h (LMDh) regulations based on the use of common parts, and Le Mans Hypercar (LMH) regulations which offer manufacturers greater freedom. The two sets of regulations are very similar, but their different conception may call for performance adjustments. To achieve this, “platform equivalence” is applied across all cars of the same type, taking on board the performance levels of the best LMDh-type car and the best LMH-type car.
The second step is “platform equivalence”. Two different technical rulebooks govern the Hypercar class: Le Mans Daytona h (LMDh) regulations based on the use of common parts, and Le Mans Hypercar (LMH) regulations which offer manufacturers greater freedom. The two sets of regulations are very similar, but their different conception may call for performance adjustments. To achieve this, “platform equivalence” is applied across all cars of the same type, taking on board the performance levels of the best LMDh-type car and the best LMH-type car.
The final step – “manufacturer compensation” – considers the individual performance of each manufacturer based on the in-race data collected. We must emphasise that “manufacturer compensations” – whatever their nature – are used sparingly and only where the data is deemed to be sufficiently robust, which takes several races.
An identical process is used for LMGT3, except that there is no “platform equivalence” as all the cars are built to the same technical regulations. A weight handicap, based on the championship standings, is added at each race except for the 24 Hours of Le Mans.
How does the process apply to the 24 Hours of Le Mans? How does BoP differ specifically for this race?
The 24 Hours of Le Mans Hypercar BoP differs in that it takes account of data from the previous year’s race, so there is not necessarily a direct link with the BoP published for the 6 Hours of Spa-Francorchamps, for instance.
For 2024, the analyses conducted by the FIA and the ACO and the restrictive nature of the applicable technical regulations have meant that BoP has been kept to a minimum. Only “homologation parameters” have been corrected based on measured data. Weight and power adjustments have been adapted on this basis to the Le Mans circuit, but no platform equivalence or manufacturer compensation have been applied. The merits of each constructor will therefore be appreciated at their just value.
We have also introduced a measure of a purely technical nature: power differentiation at low and high speed. This does not alter the actual BoP, but it does modulate the power delivered above 250 kph to balance peak speeds without the need for excessive adjustments to weight or power.
Source material - ACO
Photo credits - D Gibson/N Dungeon