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A high accuracy and low cost test protocol for the determination of the inertial characteristics of a high performance vehicle transmission is discussed. In particular, a range of NASCAR Sprint Cup race car transmission gear packages are tested and compared. The test results compare the inertial characteristics from the new CR2C transmission as developed by C&R Racing to the current standard four-speed manual version. The test protocol evaluates the inertial properties by suspending the input, output, and secondary shafts from a light weight hollow Ø1/4" x 16.58' long (Ø6.35 mm x 5.05 m) vertical torsion spring tube. An initial offset twist results in rotational cycling of the components at an easily measurable natural oscillatory period. The equations are developed for the application of the natural frequency measurements to the component inertia results.

There have been claims that the rear wing on the NASCAR Car of Tomorrow (COT) race car causes lift in the condition where the car spins during a crash and is traveling backwards down the track at high speed [1,2]. When enough lift is generated, the race car can lose control and even become airborne. At least in part, to address this concern, a new rear spoiler was designed by NASCAR to replace the wing and prevent this dangerous condition. This paper looks at the flow characteristics of both the rear wing and the new spoiler using particle image velocimetry (PIV) to provide qualitative analysis as well as flow visualization. In particular, the interaction of these downforce devices with "roof flaps" (which are designed to prevent lift) is explored. These experiments are done in a continuous flow water tunnel having a cross section of 1.0 m2 using a simplified 10% scale model COT body with either a wing or spoiler attached.