High-Precision Torque Measurement

In the sport of professional drag racing, every fraction of a second counts. For Kalitta Motorsports, maximizing performance meant collecting on-track vehicle performance data that would enable the team to optimize vehicle setup of its 8000HP Top Fuel dragster. The team needed to measure torque at engine out, clutch out, and at the wheels, which would help Kalitta determine horsepower transfer from the engine to the rear axle, conduct engine diagnostics, and improve wheel lock-out at launch.

In order for the Kalitta team to be able to take on-track measurements, the strain gage and sensor technology used had to be very compact, lightweight, and highly accurate over a range of temperatures. In addition, the data had to be transmitted wirelessly, as the mounting locations were difficult to access once the vehicle was assembled, and because the data was being collected on shafts spinning at high speeds. To meet its requirements, Kalitta used TECAT Performance Systems' WISER data acquisition/communications system and Micro-Measurements strain gages.

The strain gages were mounted to the surfaces of the engine crankshaft, the clutch, and the rear axle. Next, TECAT’s WISER systems — real-time data acquisition systems that provide resolved live torque data — were mounted to the same components and connected to the strain gages with ribbon cable. The complete systems were mounted without modifying the vehicle components themselves. This enabled the Kalitta team to build the vehicle as they would for a race, without alterations, and collect data on-track. The team has used these systems prior to races in order to optimize the vehicle setup.

The complete system, shown mounted to a test bar. The Micro-Measurements strain gage is connected to the WISER data acquisition/communications system, and both are powered from the lithium poly battery, seen at the top.

A case study document can be found at http://www.vishaypg.com/doc?25503

msaas's picture

Matt Saas

Field Design Engineer