[Vwdiesel] large pipes and diesel exhausts

[James Hansen]

Don't forget about resonance.
With some cars, when there is a loud noise out the back, it will 
resonate inside.
Why I say this, is I fiddled with this years ago on an 82 NA Jetta.
Straight pipe from front to back, with a glasspack at the factory rear 
position.
You couldn't stand it in the rear seat.  There was no noticeable change 
in the front, but you could hear the braaaap outside (enough to make the 
law look twice), and in the back seat, it was like your head was part of 
a big resonating chamber.  it really sucked for rear passengers, so I 
changed it to a high flow muffler, and that went away.

Current 97 Passat has 2.5" throughout, with a dynomax at the rear 
position.  It is pleasant, with a fair whistle outside, just noticeable 
inside.
-James




Terry Briggs wrote:
> I've been listening to a few diesels at work, a few have "normal" 
> exhaust pipes, and a couple have larger, less restrictive pipes, all 
> the ones with the larger pipes are quieter, not nearly as harsh 
> sounding and not at all tinny sounding. Noise isn't an issue with me, 
> though with the pipes going out the back, all the noise is behind you 
> anyways. but I imagine there will be a little louder sound, but at a 
> different pitch which makes a big difference.
> 
> Terry Briggs
> Third Wheel Engineering
> 2576 King Circle
> Corning, NY  14830
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