This is the current information for exhaust testing procedures. (Note: some bits may only apply to SA). Notes have been taken from various Government websites.
Exhaust dB levels in SA:
(a)for a car‑type vehicle built after Jan 1983 - 90 dB; or
(b)for a car‑type vehicle built before Dec 1982 - 96 dB; or
(c)for a motor bike or trike built after February 1985?94 dB; or
(d)for a motor bike or trike built before February 1985?100 dB.
Exhaust Outlets
For vehicles manufactured prior to July 1988 the requirements are not specific, however, vehicles submitted to Transport SA will be acceptable if:-
a. The exhaust outlet exits beyond the last door or window opening on the side or rear of the vehicle;
b. The exhaust outlet is as close as possible to the outer edge of the vehicle but not outside or underneath the vehicle;
c. The exhaust system, if contactable, is adequately shielded and any sharp or hazardous projections are suitably treated.
Exhaust Noise Testing
Many statutory bodies around the world currently mandate that vehicles comply with stationary exhaust noise tests specifications - Generally based upon the USA's "SAE J1169 Measurement of Light Vehicle Exhaust Sound Level under Stationary Conditions"
In Australia the test requirements are ADR 28/01 stationary noise test and based upon SAE J1169. In fact, the above tests have identical test procedures and only the required limit varies:
SAE J1169, USA 95 dB
ADR 28/01, Australia 90 dB
The test involves positioning a type 1, SIA compliant ANSI S1.4 - 1983 noise level meter, specifically as illustrated in the diagram below. No other positioning is relevant! Noise tests are extremely specific in their scope and must be conducted very carefully!
Diagram from SAEJ1169 Testing Procedures
Engine RPM must be held steady at 75% of rated peak horsepower RPM.
Again, it must be emphasised, all facets of a noise test must be specifically followed for the test to have any meaning.
