I'll also add that the Alfetta is particularly sensitive when it comes to
exhaust sytems. Apart from the problems involved in getting a new exhaust
to hang correctly (loosely) so it doesn't vibrate through the chassis, the
exhaust is prone to physical contact with the floor, rear engine casting and
the rear axle/suspension if not routed just right.
To add to the problems, the selection of the mufflers/resonator and their
positioning will change the exhaust note and change the 'drone' at certain
RPM. Moving the resonator an inch fore-aft has a pronounced effect.
After spending a lot of money trying to save money by having local custom
exhaust sytems fitted and modified, I would now spend that money more wisely
on a proven quality aftermarket off the shelf system. These systems will
still require some fettling to get the correct fit under the car but at
least you start from a good baseline.
One modification I do recommend though is to have an exhaust shop replace
the slip joints with quality flanges, ensuring the positioning is EXACTLY
the same your final fit-up. After getting the fit correct, and putting a few
road miles on the new system, accurately mark the exhaust slip joints for
length and rotation before dismantling.
Removing the exhaust on an Alfetta for the inevitable guibo replacement is
70% of the job!!! Flange joints make this a cinch.
Beatle
Oz
----- Original Message -----
From: "Russell Neely" <[email protected]>
To: <[email protected]>; "Tiberio Nick" <[email protected]>
Sent: Sunday, December 27, 2009 4:20 AM
Subject: Re: [alfa] Centre Muffler
The center (as opposed to centre) muffler does most of the work in
making an Alfa quiet. I once ran a welding rod through the center muffler
and
it is definitely a straight through design.
A proper sounding Alfa exhaust needs a resonator or catalyst at the
front. It needs a center muffler. The rear can be a straight pipe and
still
be quiet.
The worst sounding exhaust I ever built was a straight pipe back to a 2
1/2 inch "Turbo" style muffler on the rear. It was extremely raspy and
not at
all pleasant. That is why you need a resonator in front.
Since you are in Yurope somewhere, I bet your stock cast iron headers
are
the split style with one runner in front of the cross member and one
behind.
Those are much better than the stock 4 into 1 manifold we got in the USA.
Run the stock front head pipe with the resonator. Buy an Ansa center
section and run a straight pipe at the rear. If that is too noisy, put on
an
Ansa rear section.
I know Ansa systems do not last as long as stainless steel, but they
are
affordable.
My wife's 91 spider with the stock catalyst, the stock center muffler
and
a straight pipe at the rear was very quiet. The rear straight pipe gave
it a
bit of a proper Alfa exhaust note.
When the center muffler stress cracked, I replaced it with a Cherry
Bomb
glass pack. It is now very loud, but still has a nice tone. I have a
brand
new Ansa rear section with the single tip that looks best on the 91
spiders.
But my wife likes her spider loud, so it remains that way.
Ciao,
Russ Neely
Snowed in in Oklahoma City
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