South Australian Numbered Regulations South Australian Numbered Regulations(1) In this rule—
"vertical exhaust system" means an exhaust system that emits exhaust gases in an upward direction above or near the top of a vehicle to which the exhaust system is fitted.
(2) An outlet (a "motor trike exhaust outlet") of an exhaust system fitted to a motor trike with a permanently enclosed body must extend—
(a) at least 40 millimetres beyond the outermost joint of the floorpan that is not continuously welded or permanently sealed; and
(b) not beyond the perimeter of the vehicle.
(3) The motor trike exhaust outlet must discharge the main exhaust flow to the air—
(a) if the outlet is fitted to the side of the motor trike—to the right hand side of the motor trike and below the horizontal axis of the motor trike at an angle between 15° and 45°; or
(b) if the outlet is fitted to the rear of the motor trike—at an angle between 10° above the horizontal axis of the motor trike and 45° below that axis.
(4) An outlet (a "bus exhaust outlet") of an exhaust system fitted to a bus must be as near as practicable to the rear of the bus.
(5) If the bus is not fitted with a vertical exhaust system, the bus exhaust outlet must not extend beyond the perimeter of the bus.
(6) If the bus is fitted with a vertical exhaust system, the bus exhaust outlet must be located behind the rearmost part of the passenger compartment.
(7) A bus exhaust outlet must discharge the main exhaust flow to the air—
(a) if the outlet is not part of a vertical exhaust system—
(i) towards the rear, or to the right, of the bus; and
(ii) horizontally or downwards at an angle not more than 45° below the horizontal axis; or
(b) if the outlet is part of a vertical exhaust system—vertically upwards or towards the rear of the bus at any angle above the horizontal axis.