WIT Press


Environmental Impact Of Motorcycle Replacement Exhaust Systems In Sao Paulo City

Price

Free (open access)

Paper DOI

10.2495/SDP160541

Volume

210

Pages

12

Page Range

641 - 652

Published

2017

Size

656 kb

Copyright

WIT Press

Author(s)

A. L. S. Forcetto, L. C. Daemme

Abstract

There are about 900,000 motorcycles in the Sao Paulo Metropolitan Region (SPMR), comprising 12.2% of the vehicle fleet in 2014, with a 15% presence in the traffic flow. They contribute 23% of the Equivalent Noise Level (Leq) of road noise and are responsible for 21% of all CO, 12.8% of HC and 2.1% of NOx emissions. Non Original Exhaust Systems (NOES) can be found in 16% of the motorcycles in SPMR; these usually have no catalyser and fewer internal parts than an original exhaust system from the Original Equipment Manufacturer (OEM), in order to reduce gas flow counter-pressure and to produce a typical “popping” sound. According to users, the main reasons for using NOES are “safety”, “I like loud noise” and “performance”. Regarding noise, motorcycles equipped with NOES have a sound level 12.8 dB(A) higher than those with original exhaust systems and correspond to 62% of Leq generated from motorcycles. The use of NOES for professional “moto freighters” can result, among other occupational diseases, in Noise-Inducted Hearing Loss. With respect to gaseous emissions, NOES bring an individual increment of 1.2 to 12 times the emissions of CO, HC and NOx, compared with OEM mufflers; that adds yearly in SPMR about 1,277 t of CO, 230 t of HC and 310 t of NOx, drawing motorcycles with this equipment back to levels before Brazilian phase M3, equivalent to Euro 3.

Keywords

noise, gaseous pollution, tampered motorcycles, exhaust system