Why should a vehicle be stalled tested?

The car stall test is a test conducted on a car equipped with an automatic transmission. It essentially refers to the test of the maximum speed that the car engine can achieve when we fully press the brake pedal when we put the transmission in forward gear or reverse gear, and we press the accelerator pedal to the bottom at the same time. By testing the maximum speed that the automobile engine can achieve in the state of car stalling, the overall performance of the engine and the working performance of the various actuators of the automatic transmission can be tested.

It is worth paying special attention to the fact that when conducting the car stall test, we must first find out the working conditions of each actuator element of the transmission in different gears, so as to carry out subsequent test analysis.

When carrying out the car stall test, we should pay attention to finding a site without obstacles, and the personnel should not be close to the test vehicle, so as to prevent the car from driving out of place during the test and bringing unnecessary injury to the experimenter and the surrounding operators; At the same time, we should also pay attention to the fact that the service brake and parking brake we take should be effective and reliable at the same time, and a certain height of triangular skids should be stuffed into the front and rear wheels of the car; The engines we have tested should work normally, and all performance indicators should be good, especially the cooling system of the engine should be working well; During the whole test, we have to open the hood of the car and carefully observe the working condition of the engine. In the process of the test, there is another point that we must pay special attention to, that is, when the automobile transmission is in a stall state, the transmission oil temperature will rise sharply, the entire hydraulic system is in a state of high temperature and high pressure, and the load of the engine increases sharply, so the entire stall process can not exceed 5s.

Next, we can do the stall test as normal. First we start the engine and run it to a normal temperature, for cars without a tachometer, we install an engine tachometer for experimental data recording; Then carry out the engine stall test according to the specified operation, start the engine, put the engine in the "D" gear, press the accelerator pedal to the end at one time, and quickly read out the engine speed value displayed on the engine tachometer at the same time, and record it in time; Then we put the transmission lever in "N" gear and let the engine run in idle gear for about half a minute, which allows the torque converter to cool down sufficiently. Then we used the same method to test the stall speed of the "L" and "R" gears, and finally the stall range of the manufacturer was further analyzed.

The stall test is a method to check whether the engine output power, torque converter and automatic transmission brake and clutch related shift actuators are working properly.

The center console of the car cannot receive relevant information, the driver cannot know the condition of the car at the first time, there will be many safety hazards in the driving process, and the oxygen sensor will also malfunction.

There will be weak acceleration, increased fuel consumption, the engine cannot start normally, the speed cannot be accurately tested, and the command you launch cannot be correctly understood, which may turn 30 miles into 60 miles, causing very serious consequences.

In fact, it is easy to malfunction, and a lot of the content is not really recorded at the same time, it will also make the driver very scared, afraid of traffic accidents will also be very nervous.

1.Raise the automatic transmission oil temperature to 50 degrees Celsius to 80 degrees Celsius.

2.Secure the front and rear wheels with triangles and brake the vehicle with the parking brake.

3.Keep the engine idling and put the gear selector handle in D and R respectively for testing.

4.During the test, press the brake pedal with the left foot, and press the accelerator pedal with the right foot to the end, and quickly read the engine speed value when stable, which is called the stall speed.