FEBRUARY 2019
The Lexus RC F GT3 is equipped with a 120-liter fuel cell, the standard size required when GT3 cars are designed globally. However, in IMSA competition the governing body controls the capacity of the fuel cell in each race car to ensure they can run a stint length in the race of approximately 55 minutes before coming to pit lane to refuel. IMSA determines the stint length to ensure each class of cars competing are able to pit in sequence. While the Prototype and GTLM classes run the fastest, the GTD class cars can go the furthest distance due to the fuel capacity volume set by IMSA.
With these rules in place, the capacity of the RC F GT3 fuel cell is reduced by approximately 20 liters to 100 liters for IMSA races. This reduction in capacity size of the fuel cell is done by utilizing volume displacers -- both balls and blocks -- that are placed in the fuel cell to displace the amount of fuel. These balls and blocks are contained by a mesh bag within the fuel cell to take up volume so the team can put 100 liters of fuel into a 120-liter space. The volume of each block is approximately 0.46 liters (small) and 1.61 liters (large), while the volume of each ball, which is around the size of a baseball, is 0.18 liter.
Here is a look at the volume displacement equipment that is utilized by AIM VASSER SULLIVAN in the Lexus RC F GT3 race car:
