[alfa] Alfetta exhaust - very, very long

["Stefano Iachella" <iachella@xxxxxxxxxxxxx>]

Hey cats,

I just got my Alfetta back from the muffler/pipe bender shop
and had a few questions for people to ponder. This is quite
long and there are several items related so it might be hard to
isolate the problems and solutions.

I've had long standing problems of cracking exhaust in various
places. My exhaust is no longer stock from the Euro secondary
pipes back. Here is the work that was done. Install a flexible
coupling before the cat, install new cat (small bullet style high flow),
replace rattling center muffler with glass pack resonator, redo pipe
back over the axle, and keep existing Magnaflow brand muffler.
2" pipe was used all the way through the system.

The flexible coupling is not the kind with that braided steel, but rather
the kind with a rocking joint and springs on the bolts that hold the
flanges. It was to install this coupling that we started all the work
in the first place, since we think that a welded up exhaust on Alfettas
is not good. Kartalamakis, in his book refers, to this.

The first thing I noticed after getting the car back yesterday was
the position of the coupling. I was thinking we were going to put
it after the rubber bushing that attaches to the rear engine mount.
My thinking was the exhaust is rigid at the head, and attached to
this hard rubber bushing at the rear of the engine. After that it
needs to rock a little to accommodate the rest of the exhaust system
to the rear. It appears he installed it before the hard rubber bushing.
Any comments about that?

Other attaching points - I can observe rubber rings just after the
center muffler attached to the body at factory points, and the muffler
has hard rubber hangers before and after it. This leaves the pipe
over the axle with no support. I can grab the loop over the axle
and rock it up and down very easily. It imparts a substantial twist
on the whole exhaust system, all the way to the coupling up front.
It touches the sway bar mount as well. It has improved however;
as it used to rattle upon acceleration, when the car squats, AND
on a left turn, when the pipe would swing to the right and hit the
sway bar mount. Now it only hits on acceleration when the rear of
the car squats. But I'm concerned with this twisting. My Ansa
catalog shows a drawing of the rear exhaust with a support very near
the top of the loop above the right rear axle. I think I feel a bolt hole
on the body in that area. Should I get this mounted up? I've heard
Alfettas are sensitive to the mounting points and too many are bad.
In this regard, should I eliminate one of the muffler mounting points
(before the muffler) when this is done to leave proper movement?

My muffler guy is not too familiar with Alfas so I'm guiding him through
all this as I learn the do's and don'ts of Alfetta exhaust, but he's
convinced that there is a vibration that is causing my exhaust to crack
all of the time. After this last work, all the bad noises have subsided
and things seem pretty smooth. I don't observe any drive shaft vibration.
I have noticed something with the left motor mount, though. Years ago
when swapping an engine, the mechanic told me he had to do some
welding to the motor mount. I can see the welding to the metal "V" part
of the mount. The rubber part has been replaced since, but it doesn't
seem straight. The body part doesn't line up with the "V" part and the
rubber is a bit distorted. Could the engine being slightly cocked to the
right cause any of the problems?

One final thought - it has been suggested to me that if the new material
in the pipe and the old material of the existing portions are not quite the
same gauge, there could be potential to crack at this junction. At this
moment, the only place of old/new junction is where the Euro secondaries
come together and are welded to this flexible coupling. It was suggested
to weld a "fishplate" as it was called, under this location. This would be a
triangular piece of steel to support the junction similar to what many OEM
mufflers have holding the pipe to the muffler steady. Any thoughts on this
idea?

Sorry to take so much space to explain all of this. Thanks for reading it
all,
and hope I explained it well enough for someone to throw out some ideas.
I'm going back to the muffler shop to pay him Monday morning, so I hope
some of you are reading this Sunday night.

Thanks,
Stefano
Oakland, CA
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