SILENCING : Exhaust systems are free .
All vehicles must comply with the maximum decibel level as laid down in the MSA Yearbook 2016 ( GR J 5.16 -- 5.18 ) .
SILENCING : Exhaust systems are free but all vehicles must comply with the maximum decibel level as laid down in the MSA Yearbook 2016 ( GR J 5.16 -- 5.18 ) .