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Power Requirement Programme
This programme can be used for calculating the power requirement for any vehicle to travel at a required velocity given the CDA, CRR and vehicle mass. Alternatively, if the top speed of a vehicle is known - as well as the power to the wheels at this speed - then the CDA can be calculated given the CRR and vehicle mass.
Example - Calculate Power Requirement
For this example we wish to calculate the power required to obtain a top speed of 168 km/hr for a small capacity racing motorcycle. The CDA is known to be 0.225 with the rider in a tucked position and the all up mass is 150 kg.
The power is calculated at 14.7 kW - 19.7 bhp.
Example - Calculate CDA
For this example we are using a car manufactured by Renault. It is a turbo diesel with a claimed maximum power output of 118 bhp. This number is multiplied by the drive train efficiency of 0.86 to arrive at 101.48 bhp at the wheels. The diagram below shows the computed CDA as 0.712 m2 - 7.668 ft2.
The programme is perfect for setting up a motorcycle or streamliner for Bonneville. If you have a target speed that you wish to achieve, then you can calculate the power requirement to reach this speed.