IS THE FACTORY FITTED EXHAUST STAINLESS OR MILD STEEL

[SCHOLESY83]

Hi,

Does anyone know if standard exhaust on the S3 is stainless steel? 2007 model in particular?

With the price of it, one would assume it is!!

Cheers

 

[mjr901]

I have a full system from a 3 door 2012 S3, its done less than 1k if your interested.

 

[SCHOLESY83]

Cheers. Will PM you if I go down that route.

as for my original question, any ideas??

 

[mjr901]

mild steel, it's heavy....very heavy...

Where as my Milltek was not...

 

[SCHOLESY83]

Going slightly off topic but how have you found the miltek? Any issues?

oh and Audi service technicians says the standard exhaust is Stainless..... Hmmmm

 

[mjr901]

It's well heavy, I'm certainly no metal expert, but it's not shiny like the millteks, so I assume it's mild steel. Probably very wrong.

As for the Milltek, Sounds good, but welds on the downpipe are almost certain to crack at some point and need re welding.

 

[Boon]

Mild steel is magnetic wheras stainless is not... try a magnet on it

 

[mjr901]

just did the magnetic trick.

All the pipes are not magnetic.

All boxes are.

So semi Stainless??

 

[Rom]

Id think Audi use stainless for the exhausts. Toyota have done for years (apart from Aygo) so surely Audi would.

There are many grades of stainless though, which is why they wont look like an aftermarket system. They use a higher grade, which is shiny. Obviously OEM are just interested in it lasting a long time, not looking shiny.

Thats why exhausts are a lot less common to replace on more modern cars.

 

[PaulAr]

Stainless classification starts with 12% Cr content.
Most exhausts are `18/8 grade` (18Chrome/8Nickel) which are Austenitic.
Generaly 304 designation for exhausts.

Milltek gives big gains but welds can crack.

Make sure your warranty is sound.

Spicy pizzas n garlic sauce work well.

good luck

 

[SCHOLESY83]

Did the magnetic check too, I found that all pipes and both large boxes (mid & rear) were non magnetic - suggesting stainless. Cat and smallest box as well as the chunky bit straight after turbo connection were magnetic - suggesting non stainless.

Thanks for your input guys.

 

[SCHOLESY83]

Disappointing to here about the Milltek cracking issue. Surely this is covered by their corrosion and manufacturing defect warranty??

 

[Bazzle]

Some stainless pipes etc are magnetic. Normally those that are more malleable.
Work hardening can also make austenitic stainless steels slightly magnetic