Quote:
Originally Posted by Armonster
I wonder if some cat backs are better at eliminating the hiss than others.
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I'm sure they are. The hiss is probably exhaust gasses bouncing around in the y-pipe. It's weird to me that you hear it under acceleration though. I notice it some when cruising, but only if I'm driving next to a wall that the sound can bounce back off of.
If I'm stationary and revving, I only hear the hiss when the RPM's are dropping back down.. Or at least, the hiss is slightly there under cruising or revving, but very pronounced when the RPM's are falling, specifically in a certain range (from about 3500-2000).
I'm not engine/exhaust expert.. so maybe this will help Tony explain where the sound/gas characteristics come from..