Engine Performance Project/Lab Ideas

•Students will work in teams to use mathematical skills to manipulate physics formulas and equations.  Students will use their results to show how vehicle speed, engine speed, and engine torque impact a vehicle’s ability to go up a hill without the transmission down shifting.

•Have students determine the rear axle ratio by raising a tire and putting a chalk mark on the raised tire and drive shaft.  Turn the tire two revolutions and count the turns of the drive shaft.  This is the rear axle ratio.  Measure the outside tire diameter of the vehicle.  Use this information to convert the speed of the vehicle in mph to engine rpm as follows.  Convert velocity in mph to feet per min.  Divide velocity in feet per min by the circumference of the tire to get the rpm of the tire at that velocity.  Then multiply the tire rpm by the rear axle ratio to get engine rpm.

 

Velocity_mph = Velocity_fpm

rpm_tire = Velocity_fpm / Tire Circumference

rpm_engine = rpm_tire x Rear axle ratio

Ask students to reflect on their capacity to be automotive technicians.

 

•Have students demonstrate their knowledge of the combustion process using their mathematical skills and the gas laws of physics.  Students can relate this process by using a gas analyzer to interpret and diagnose engine conditions.