Changes in the noise reduction level of mufflers (aftermarket and performance mufflers)
There is a difference between “aftermarket” mufflers and “performance” mufflers. Aftermarket mufflers are designed in accordance with BMW specifications for mufflers produced after the introduction of new German legislation in the 1950s. Performance mufflers are designed according to pre-1953 specifications. Example: P/N 18124090003 Muffler “Fish tail” – RH – after market P/N 18124090003RDH Muffler “Fish tail” – RH – for optimal performance Background: Between 1951 and 1953, West Germany introduced more uniform vehicle regulations These were incorporated into the Straßenverkehrs-Zulassungs-Ordnung (StVZO) Around 1953, stricter requirements for exhaust noise (“Geräuschentwicklung”) were introduced Before this (late 1940s / early 1950s): Exhaust systems were relatively lightly
Read more »