Draft presentation on the amendments developed by the informal working group on Additional Sound Emission Provisions.

Updated version of document GRB/2017/2 pursuant to discussions during the 2nd ASEP II informal group session.

OICA proposal to provide a clearer and more precise definition for “stable acceleration”. The definition introduced in document GRB/2017/02 is specified as "when the acceleration from line AA’ to PP’ has a low variation to the acceleration from line PP’ to BB’.” The term “low variation” is imprecise and so OICA proposes the wording “when the acceleration ratio a_{(PP’-BB’)}/a_{(AA’-BB’)} is lower than 1,2.”

Discussion of current issues related to vehicle noise levels, especially given the availability of affordable electronic devices that enable car owners to artificially increase vehicle sound output.

Presentation of concerns and possible responses through GRB regarding vehicle noise, especially related to system tampering and vehicle modifications.

Presentation updated to include revisions to the working document GRB/2017/2 as agreed during the 2nd ASEP II informal group session to be presented during GRB-65 as an informal document amending the draft Supplement 2 to the 03 series of amendments to UN R51.

Presentation concerning vehicle noise relationship to speed and acceleration and other factors

Modification of the proposal to enable indoor testing under UN R51 on vehicle noise.

Measurement Setup Scheme for Stationary Sound Emission Test – Engine Proximity: Stationary Run-Up Measurement (SLOW run-up) from IDLE to Govern Engine Speed

ASEP data file for 5-1-2 noise limits as of 13 June 2017.

ASEP data file for L_urban noise limits as of 13 July 2017.

UN R51 allows the use mechanical or electronic devices to control the gear shifting and measures to avoid accelerations greater than 2.0 m/s². However, the measures are not defined and the manufacturer or technical service is not obliged to document the methodology in the test report. This proposal would introduce a table with examples for devices and measures for reference and would require documentation of methodology used.

Japan presentation on tests conducted and questions raised.

French ASEP test validation results and questions/difficulties encountered.

OICA presentation on modeling, including tire rolling noise and power train noise, of vehicle sound emissions and compliance with UN R51 requirements.