[s-cars] Re: Noisy Stromung in the rain

[William Noland]

In general, Scott, higher humidity levels result in more sound
attenuation (absorption).  The results are more dramatic for higher
frequency sounds -- the higher the humidity, the more sound levels drop
relative to lower frequency sounds. The attenuation (loss of sound
volume) of very low frequencies of sound actually rises with humidity
(say to around 50%, or so), then drops off . So low frequency sounds, at
a constant distance, sound louder at 100% humidity, than at 50%.
Opposite is true for high frequency sounds. So, your Stromung's bass
gets a boost and treble falls off.

Why the turbo whistle (a relatively high frequency) would sound louder
is beyond me. Perhaps because your windows are up in the rain, which
would cut out some high frequency wind noise and down when it's dry?
Help me out here guys. Is there a fizzy-sist in the house?  :-)

Bill Noland
in the dry season in Northern California


>Not that it ever rains in Columbus, OH, but anyone
>have a theory on why the Stromung exhaust on my 92
>suddenly gets LOUD when driving through heavy-rain
>soaked roads?  Turbo also whistles louder on any
>slight throttle responses (did it with the K24 and the
>current RS2).  During these episodes, I can feel a
>little decrease in power available.  Never, ever did
>it loud in the rain.  Capital LOUD.
>
>Exhaust and turbo noise abates immediately as soon as
>road conditions dry out.
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