Subject: re: stainless exhaust

[S. Jaworski]

Lets not be so sensitive. If what you say does'nt make sense to someone,
he/she has a right to ask questions. I did not notice any name calling in
the replies . . . . listers merely made their comments based on factors that
conflict with your opinion. If 2 plus 2 adds up to 3, some people(yours
truly) will ask pointed questions.

Tess might be right . . .for the wrong reasons. SS may not be worth the
trouble for racing purposes - its more difficult to fabricate, doesnt hold
up to high heat(exhaust headers), and its a bitch to weld correctly.
Corrosion from salt, and corrosion from short ride water condensation is not
an issue in racing. But, for street use, these are important considerations.
There are some fabricators who know how to choose the correct material and
they know how to work with it. And for this purpose, the higher cost is
warranted by the much longer lifespan over standard exhaust materials.

For your entertainment, a quick internet search about Stainless Steel
produced the following:

-the grade of stainless used by dodge is type 409 stainless, it is magnetic
and has good corrossion resistance, a very good example is your silverware,
it is stainless and a magnet will stick to it like glue, it is type 430 , i
use type 304 on my exhaust systems, it is non magnetic and far superior to
409 like many grades of steel, stainless comes in many different
compositions.


-Although stainless steel doesn't rust in the same way as mild steel, it can
still suffer from the elements, and joining stainless components is more
complicated than mild steel, since molecular changes can occur when welding
stainless steel which weaken the joint and make it prone to cracking


-Every year, many millions of exhaust systems are replaced by North American
car owners at enormous cost becuase the typical life of a conventional car
exhaust system is one or two seasons. Even aluminized mild steel systems
last only two seasons because the superficial protective coating is damaged
during welding, perforation, fitting and service use.
The British Steel Corporation, after much research, has developed a type of
stainless steel called "Hyform 409" which is designed for exhaust system
use. It is the best trade-off between orrosion resistance, formability,
fatigue life and weld acceptability.



-http://www.haywardandscott.co.uk/porsche_world.htm
Exhaust systems mean different things to different people. For some, they're
no more than disposables that rust away as surely as night follows day -
usually a week before the annual MoT test is due. For others, a shiny
tailpipe the size of the Channel Tunnel is a sign of virility (or lack of
it, depending upon your point of view).


-http://pw1.netcom.com/~dwelding/stainless.htm
Lots of good info here.
What is STAINLESS STEEL?
Stainless steel is a family of iron based alloys that must contain at least
10.5% CHROMIUM (Cr). The presence of chromium creates an invisible surface
film that resists oxidation and makes the material "passive" or corrosion
resistant (i.e. "stainless"). This family can be simply and logically
grouped into five (5) branches. Each of these branches has specific
properties and a basic grade or "type." In addition, further alloy
modifications can be made to "tailored" the chemical composition to meet the
needs of different corrosion conditions, temperature ranges, strength
requirements, or to improve weldability, machinability, work hardening and
formability.


-http://engineeronline.ws/elmes/stainless.htm
Information about welding SS and associated problems. If you dont weld it
right, the welds will corrode.

Keep in mind that this is a Martian enclave. If you're from Venus, you might
want to learn Martian-speak. "Why cant we just get along?" does'nt work on
this planet.  Hey, just kidding . . . .  :-)


Syl

88 5KQ
90 100Q



> From: "Tessie McMillan" <tessmc at drizzle.com>
> To: "Quattro at Audifans. Com" <quattro at audifans.com>
> Subject: re: stainless exhaust
> Date: Sat, 4 Aug 2001 12:29:31 -0700
>
> Hey! Before any more of you rag on me about my comments on stainless, I'll
> say this: Before I put the glasspack and magnaflow on my Quattro, I was
> hell-bent on putting a stainless system on my car. The header guy (who is
> used by many in the racing community up here) refused, for the reasons
that
> I gave in my post. My mechanic agreed, for the reasons I stated in my
post.
>
> Please don't tell me "I have my facts wrong", because I have different
> information than you and the people I'm working with have different
outcomes
> than you. That's just plain rude! I'm also under the impression that not
all
> the stainless systems are stainless through and through, they are only
> stainless on the outside.
>
> If your mileage varies, that's fine with me! Please state your
experiences,
> we will learn from them. Don't call me names or undermine me as a person.
> That's plain *rude* and is not appropriate for this forum.
>
> Tess