Technically, a muffler quiets the engine by reducing the sound pressure emitted. The factory mufflers on your Mustang are made to sound good, but are restricted by efficiency concerns, ease and cost of manufacturing, and of course sound level laws. For many enthusiasts, the stock mufflers are too conservative.
RE: nominal. 25 Aug 06 13:08. A nominal dimension is one which the tolerance is based from, which is not necessarily the optimum size. A dimension can have a Push Fit or Press Fit tolerance of say +.001/+.003 showing that the actual nominal is NOT what is required.
Nominalization refers to the creation of a noun from verbs or adjectives. Most of the time, nouns are created from other parts of speech through the use of suffixes. In other cases, the word remains the same but is simply used a different way; this is known as conversion or zero derivation.