[alfa] Exhaust note question

[Jon Pike <jhpike@xxxxxxx>]

> Speaking of exhausts (in the Ansa/Stebro thread), I have an Ansa twin-tip
> exhaust on my 84 spider.  I have a very noticable tinny vibration sound and
> I can't seem to identify the source.  Could it be from the cat?  I have no
> other reference to know what the Ansa system should sound like.  I can
> clearly hear what sounds like a stick being dragged up and down a washboard
> very quickly, and the exhaust note reminds me of an old VW bug sound.  It is
> most noticable after i've released the accelerator (after revving the
> engine).  I have recorded the sound and uploaded the file here:
Wow,  that is wierd,  Greg...

Did it just start up,  or was it like this from the moment you put on 
the Ansa? 
It sounds like you have something loose,  cracked baffle or something 
somewhere in there. The boomyness and tin can like sounds could be 
caused by that.  That high pitched whistle is very strange, must be just 
the right airflow over the defect.

I'm not the exhaust expert you want,  but I do kind of remember the 
couple of Ansa's I had on 74 Spiders back about 16-20yrs ago..  they 
didn't sound like that. Take away some of the tin can resonance, and the 
whistle,  and you have an idea of the sound.

I'd suggest a step by step troubleshooting..  which you can do if you 
have another end piece.  If you can,  change to another to see if it's 
still there.  I wouldn't reccomend running without the end piece for 
very long, but for a few revs in the garage it should be OK. You could 
try that if you don't have or can't borrow a different tailpiece.

BTW, I did this with my first Spider,  while working on the exhaust.  
Without the tail section the car was LOUD.. unbeliviable bass at certain 
revs..  Being in my 20's at the time,  I just had to go roaring around 
the neighborhood to properly experience this..  and found out that I'd 
almost cooked my rubber mat in back,  and melted holes in the fuel vapor 
recovery lines.  Very hot exhaust blowing up on the underbody is not a 
good thing..

Hope it helps..

Jon and Marcia
77 Spider
Irvine, CA
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