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Addendum 40: Regulation 41, Rev. 2
All three tests are equally important for compliance with standards, but the second one is more rigorous in terms of variables that are defined for the needed test. Formula (PMR) based on motor vehicle power and kerb weight define parameters for constant speed and full throttle tests.
Constant speed test is divided into two categories – 40 km/h and 50 km/h based on the formula mentioned above. This part of the test is very simple and the vehicle just needs to pass the measurement track with the required speed.
Full throttle acceleration test is much more complex in terms of practical execution. Following are the conditions that have to be met in order for measurement to be according to the new regulation:
Tests should be performed without gear changes. If a given gear cannot meet the conditions of acceleration within 10%, two gears are used (a gear with higher acceleration and the next gear with lower acceleration). If rated engine speed is exceeded in a gear before reaching the end of the track, a higher gear should be used. If a vehicle has more than one gear, a gear higher than the first should be used.
For automatic and CVT transmissions a gear shift into a higher gear and higher acceleration is allowed. It is permitted to introduce a device that prevent downshifts if they are not a typical part of normal operation for given conditions.
At least three measurements should be performed on each side of the vehicle and for each gear.
The last test is perhaps the simplest in terms of facilities and needed space. Vehicle should be put to neutral gear. During the test, engine hood needs to remain closed. In case of no neutral gear available, the test should be carried out with rear wheel raised from the ground. On the other hand, this test has a detailed procedure of measurements and durations that need to be fulfilled for the measurement to be correct. Requirements for the test are:
Prescribed RPM signature measurement where engine speed goes from idle, to either 50% or 75% engine speed and then back to idle. The procedure is crucial and can be very simple or quite complicated depending on the equipment used to control and monitor all the relevant parameters without opening the engine compartment. The stationary noise test takes the least time and preparation. It is a very good indicator for both tests where motorcycle is moving. The regulation will be in effect very soon and measurements will be crucial.
Noise Patrol puts fears to rest when it comes to measuring stationary exhaust noise which is at the same time first condition for any further measurements. With its advanced IntelliRevTM package for RPM acquisition, the system is now a complete all-in-one solution for stationary noise tests of motor vehicles.
The three tests are all mandatory for state approval of the vehicle to be used on public roads. And the fact that the first two tests are complicated because they evaluate the vehicle as a model for all subsequent vehicles of the same type. This makes the Stationary exhaust test even more relevant. Because that is the one that is in some countries even a requirement for passing the obligatory technical inspection. It is also used by police to quickly and efficiently determine the deviation from the original vehicle as is stated by the manufacturer.
Because these tests are performed consistently through the cycle of a motor vehicle speed and efficiency of such measurements is the key. And Noise Patrol is an all in one solution to perform measurements of stationary exhaust noise every day with ease and reliability.