ISV Muffler - Question
09-17-2007, 12:21 AM
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ISV Muffler - Question
Hi,
I noticed the ISV on my car doesn't have the muffler that '92 or '91? and up have.. it has a hose instead, I wonder what made Porsche changed that... too noisy? Harder to pass emitions? Gumming up the ISV more that it should?
I haven't heard any difference on how newer engines sound compare to my 90.
Anyone have any ideas?
I noticed the ISV on my car doesn't have the muffler that '92 or '91? and up have.. it has a hose instead, I wonder what made Porsche changed that... too noisy? Harder to pass emitions? Gumming up the ISV more that it should?
I haven't heard any difference on how newer engines sound compare to my 90.
Anyone have any ideas?
09-17-2007, 01:23 AM
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It likely "smooths" out the ISV effect on air-flow which produces a smoother idle response when the valve is actuated. I don't think it has anything to do with sound, but air flow instead. I would assume it's similar to how an exhaust system muffler smooths out the blasts of air coming from the combustion chambers...
