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Car Performance Tests

Learn what tests to do on your car in order to evaluate its performance.


Breaking Horse Power (BHP)
Dyno Test See what horsepower your car has with a dynamometer, the dynamometer applies various loads on the engine and measures the engine's ability to move the load. The dynamometer may be connected to a computer which calculates the output of the engine. The engine is run from idle to its maximum RPM and the output is measured and plotted on a graph. Nearly all aspects of engine operation are measured during a dyno run.
An engine dynamometer measures power and torque directly from the engine's crankshaft (or flywheel), when the engine is removed from the vehicle. These dynos do not account for power losses in the drivetrain, such as the gearbox, transmission or differential etc.
A chassis dynamometer measures power from the engine through the wheels. The vehicle is parked on rollers which the car then turns and the output is measured. These dynos can be fixed or portable.
Because of frictional and mechanical losses in the various drivetrain components, the measured horsepower is generally 15-20 percent less than the brake horsepower measured at the crankshaft or flywheel on an engine dynamometer.
Horsepower and torque figures are a strong predictor but do not guarantee a specific 0-60 MPH or 1/4 mile E.T. (elapsed time). An engine accelerating in a vehicle experiences different conditions than on a dyno. G forces and different temperatures as well as different modes of vibration in a vehicle can cause significant differences in power output.
Compression Ratio
Compression Ratio Test The compression ratio is a single number that can be used to predict the performance of any internal-combustion engine. It is a ratio between the volume of a combustion chamber and cylinder when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The higher the compression ratio, the more mechanical energy an engine can squeeze from its air-fuel mixture. Higher compression ratios, however, also make detonation more likely. Due to pinging (detonation), the CR in a gasoline/petrol or LPG or CNG-powered engine will usually not be much higher than 10:1.
In engines with a ping or knock sensor and an electronic control unit, the CR can be as high as 13:1 (2005 BMW K1200S)
In a turbo charged or super charged engine the CR will be around 8.5:1
In a diesel engine the CR will be 14:1 and higher.
1/4 Mile or Quarter Mile
Quarter Mile The Quarter Mile (402 meters, 440 yards, or 1,320 feet) is a distance generally used for racing two objects, and it an excellent way to compare the speed and acceleration of two objects. The race is generally begun with a standing start which allows three factors to affect the outcome of the race: reaction time, acceleration and speed. The most common example use of this distance is in automobile Drag Racing.
0-60 mph
0-60 0 to 60 is how to measure the acceleration of your vehicle it is the time it takes your vehicle to get from standing to 60 mph.
 
 
   
 
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