PSE for 987 Owners!!!

Mark, you should enter "C" class for the Concours. This is exterior, interior and both trunks. At least this is how the Chicago PCA does it.


OK, so what is "resonance" and what does that sound like? I understand that resonance is a bad thing.

Thanks.

[Houston C4S]

"Mark, you should enter "C" class for the Concours. This is exterior, interior and both trunks. At least this is how the Chicago PCA does it."


Well, I have only done one of these more than two years ago (in the C4S)
and what's left of my brain does not recall what classes they have. They
are not too strict around here, preferring that they get more folks to
participate knowing that no one is going to wipe the upper disgronificators
with a white glove or check for cracks in the fallopian tubes.

So we will see.



"OK, so what is "resonance" and what does that sound like? I understand that resonance is a bad thing."

Resonance occurs with many things.

From the American Heritage Dictionary:

American Heritage Dictionary - Cite This Source
res·o·nance (r?z'?-n?ns) Pronunciation Key
n.
The quality or condition of being resonant: words that had resonance throughout his life.

Richness or significance, especially in evoking an association or strong emotion: "It is home and family that give resonance . . . to life" (George Gilder). "Israel, gateway to Mecca, is of course a land of religious resonance and geopolitical significance" (James Wolcott).

Physics: The increase in amplitude of oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system.

Physic:s A subatomic particle lasting too short a time to be observed directly. The existence of such particles is usually inferred from a peak in the energy distribution of its decay products.


Acoustics: Intensification and prolongation of sound, especially of a musical tone, produced by sympathetic vibration.


Linguistics: Intensification of vocal tones during articulation, as by the air cavities of the mouth and nasal passages.

Medicine: The sound produced by diagnostic percussion of the normal chest.

Chemistry: The property of a compound having simultaneously the characteristics of two or more structural forms that differ only in the distribution of electrons. Such compounds are highly stable and cannot be properly represented by a single structural formula."



Note particularly the section "Acoustics." That is what happens when there is
a range of rpm where the sound produced by the combusition taking place
in the cylinders gets louder than at other rpm ranges. It would seem that
most aftermarket "systems" allow the sound to resonate around 2,500 -
3,000 rpm. That means it gets LOUD at that rpm, sometimes obnoxiously so.

But under or over that range they are not overly loud.

The factory boffins are real engineers and have big budgets and can
make the engines sound pretty much any way they want. And do so
with amazingly high flow rates with low pressure.

Does that help?

- Mark

Thank you, Houston!

[z12358]

bmuss, the first physics resonance definition is more relevant for this case.

"Physics: The increase in amplitude of oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system."

So when resonance happens with most aftermarket exhausts it usually causes mechanical vibrations, as well (in addition to the air-borne waves i.e. amplified sound). IMO, that's what really makes them undesirable to people who dislike them. Designing an acoustical system is not unlike designing an electic RLC circuit, and is far from trivial. Hence, the top $ demanded by Porsche for their smooth sounding PSE. Those engineers have mortgages to pay.

Z.

[SD987]

Super66, it sounds like you're describing the 986 PSE, which looks very cool imnsho.

Great photo, SD987...where did you get it? I like the Porsche crest on the rear trunk lid.

[super66]

Originally Posted by SD987

Super66, it sounds like you're describing the 986 PSE, which looks very cool imnsho.

as al Bundy would say, that's it! that's my song! ha ha hmmm....

so I take it those tips wouldn't work on a 987?

Originally Posted by super66

as al Bundy would say, that's it! that's my song! ha ha hmmm....

so I take it those tips wouldn't work on a 987?

Super66, that is an entire exhaust system, not just tips. And that PSE won't fit on the 987. Looks great, though!