Balance of Performance — Why Cars Get Ballast

• Weight

  Adding or removing ballast changes a car’s minimum weight — the most visible lever. A heavier car accelerates, brakes and corners slightly slower.

• Engine power

  Capping maximum power (often via the engine management map) trims the advantage of a strong engine, especially down the long straights of circuits like Le Mans.

• Aerodynamics

  Adjusting permitted downforce or drag shifts the balance between cars that are strong in the corners and cars that are strong on the straights.

• Engine management

  The electronic limits a car runs to — used to fine-tune how much of the engine’s potential a team can actually deploy.

• Why it exists

  Sportscar grids mix very different cars — different engines, layouts, and (in the top class) two whole rulebooks in LMH and LMDh. BoP lets all of them race for the win on the same lap, instead of the field being decided by who showed up with the best base car. Without it, one manufacturer’s package could dominate for a season.

• Each series runs its own

  There is no single global BoP. IMSA sets BoP for its WeatherTech championship; the ACO sets it for the WEC and the 24 Hours of Le Mans. The same car can therefore carry different ballast and power in different series — and at Le Mans specifically, the organiser can publish a one-off BoP for the race.

• It can change at any time

  Organisers can adjust BoP at any point in the season, including between rounds and even for a single event. That responsiveness is the point — it lets the balance be corrected when one car proves too quick — but it’s also why BoP is argued about every weekend.

• Sandbagging — the cat-and-mouse game

  Because BoP is partly set from observed pace, teams are accused of "sandbagging" — running slower than their true pace in testing and practice to earn a softer BoP. Rivals accused the Ford GT of sandbagging during the 2016 WEC season, and IMSA has gone as far as mandating a five-minute stop-and-go penalty for any car found sandbagging during the Roar Before the 24 pre-season test.

• 2016

  Ford GT and the Le Mans BoP row

  After the Ford GT dominated qualifying at the 2016 24 Hours of Le Mans, its performance was adjusted for the race — and rival teams accused the Ganassi-run programme of sandbagging across the 2016 WEC season to game the system. It became the textbook example of how BoP turns raw pace into a strategic guessing game.

  Source: Wikipedia, Balance of Performance

BoP FAQ

More sportscar guides

• Multi-Class Racing ExplainedWhy a car can finish 30th overall and still win — GTP, LMP2, GTD and the per-class result
• LMDh vs LMHThe two top-class rulebooks that race together at Le Mans — and what actually differs
• FIA Driver CategoriesPlatinum, Gold, Silver, Bronze — and why a class can require an amateur in the car
• Sportscar ChampionshipsThe Michelin Endurance Cup, the layered IMSA titles, and WEC’s per-class crowns
• Rolex 24 hubWhere BoP is argued about every January