Insight: Torque Sensors and Virtual Energy Explained by Ford Engineers

Sportscar365 asks Ford Performance engineers for further insight into IMSA's newly adopted torque sensors for the GT classes and it's impact on racing...

January’s Rolex 24 at Daytona marked the start of a new era for the GTD Pro and GTD classes in the IMSA WeatherTech SportsCar Championship, with the introduction of torque sensors to the production-based classes.

It not only brought in a new foundation to the Balance of Performance system but the season kick-off also marked a first-time victory for Mustang GT3 globally and Ford Multimatic Motorsports in the GTD Pro class.

The factory Mustang GT3 program, in its second season of competition, triumphed in the highly competitive category that has seen a significant overhaul to the way performance and efficiency is measured.

First introduced in the LMH and LMDh platforms of top class prototype racing several years ago, torque sensors made its GT class debut in the LMGT3 ranks of the FIA World Endurance Championship in 2024.

The sensors, attached to the driveshafts of each car, are effectively used as an on-board dynamometer, which relays precise drivetrain data to control units that regulate performance. The data is also transmitted directly to the sanctioning bodies, which establish parameters through its Balance of Performance.

"One of the cool things about torque meters is that it's as close of a sensor as you can get to the tires without putting something physically on the wheel,” explains Anthony Klepacki, Ford Performance sports car motorsport program engineer.

In addition to regulating power output, torque sensors are also used to measure energy efficiency. Gone are the days of capacity measured in liters of fuel. Instead, GT3 cars in the WEC and WeatherTech Championship now adhere to the so-called ‘virtual energy’ that’s measured in megajoules (MJ) of energy per stint.