[alfa] Smoggy Smoggy!

[Jon Pike <jhpike@xxxxxxx>]

Hi Ben..

Did this myself in the 77 not too many months ago,  after the rebuild.  
I had what must have been
the original cat (pancake hatbox kind of shape, much rattling) which I 
got rid of for an aftermarket
one.  Had all the original airpump equipment,  don't know if it helped 
or not but opened the pump
to clean it and try to quiet it down.. much crud came out and it seemed 
to move more air as I spun it,
as well as got quieter.  Almost wrecked it in the process of opening.. 
be very cautious. Maybe you don't
want to play with it if it's not making too horrible of noises and still 
blowing air...

I gave the Spica a full adjustment (get Wes's book, and or follow the 
earlier mentioned thread), and set the spark for correct advance at idle 
rather than maximum, visited a gracious mechanic who had an old engine 
analyzer and set for about 1% CO while still on the old dead cat, 
assuming that would be more accurate than with the new one.  Oh, I did 
have the drive belt off the airpump.. also on the assumption that that 
would give a more accurate setting without extra air being injected.

Put the new cat on, airpump belt on, went down there and flew thru on 
NOx, while squeaking under on
the CO limit. 
You being high on CO of course, says you're rich, you need to find a 
analyzer you can use to lean things out when you set up the Spica. The 
smog people will NOT let you use theirs,  you gotta find someone with an 
older one.  Or, get a wideband O2 sensor/meter like I later did..  
(another story..)  Leaning out too much will drive the NOx up, while 
leaving you with low CO..

For your question, I'd suggest a new cat,  and whatever else you want 
behind..  The stock Alfa exhaust system
is pretty free flowing as is..  I remember having this discussion about 
20 years ago with my mechanic, and he
really thought there wasn't that much more to get by going to custom 
larger stuff. Now, upstream, the 72-74 headers and downpipe ARE larger, 
but that's another story, as well as a non smog compatible one..  ;-)
I've also heard that having a "chamber" there, at the end of the 
downpipe part of the header system, helps them work better..  it does 
sound deeper and rounder with the cat than when I have the test pipe on..

You can either buy a pre fitted one or have a muffler shop put one 
together for you.  Problem #1, the Alfa flange for the cat is apparently 
nearly unique.. spent many hours at many shops trying to ID it and 
couldn't. Finally was looking at having a laser cutting place make 
some,  would have been pricy! (But if there's interest,
a group buy might make them almost reasonable... uh, let me know!)  But 
they can cut the two off your old cat,
and use them.  Advantage is, you'll have a custom fit.. disadvantage is 
the greater hasssle.  Also, you could have totally new flanges on both 
sides put on, in a more common size,  but then you have a non-standard 
exhaust system.. and it's more welding and hassle..

If you do this, the Magnaflow 94100 looks to be the right choice in 
size.  There seems to be only a couple of
cat lines out there,  despite many more brand names..  I went with a pre 
made one, which fit with some tweaking.

Hope it helps..

Jon and Marcia
77 Spider
97 Saturn
94 Neon
81 380 SL (yeah not an Alfa but it was FREE!!)
2 Car Garage 
How did this happen??  (and we were looking at a 95 164 the other 
day!!)  ;-)


> Gentle Alfisti-
>
> Here in the People's Republic of California, I have managed to avoid 
> until this moment having to smog my beloved '78 Spider. But the dreaded 
> time arrives. I'm fine on the Nox (NOx?) and all the other stuff, but 
> my hydrocarbon levels are killing me. While I'm saving up to do the 
> required updates/repairs, I figured I'd look into doing what I can for 
> (smoggable) performance. So FINALLY, the question:
>
> What high-flow exhaust/cat option opinions are to be had from all 
> y'all? Please remember that this does have to pass smog, so no straight 
> pipes. Yet. Basically, cat and back, what is my best option? I'm gonna 
> leave the question open in an effort to spark the dreaded discussion. 
> Bwahahaha (sorry, it's early).
>
> Thanks in advance,
> Ben Kaupp, Santa Cruz
> '78 Spider (just got 2nd in my first TSD. Thanks ARA folks, it was a 
> blast!)
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