In my ever increasing facination with exhuast design and construction my recent dialouge with David Buschur lead me down a road which ended at a Ace Hardwear store in Tuscon AZ testing a china made popular exhuast to see if its flanges were stainess steel or not

300 grade stainless commonly used in high performance exhuasts is non magnetic for reasons that escape me but which seem to make sense to the scientific world

http://www.sciam.com/askexpert_quest...1F83414B7FFEB5

This is the so called "magnet test" which you can do in conjunction with the now famous "beer car test" to check out your china made exhuast to see if you got ripped off with chrome plated steel flanges which will rust

Real performance stainless exhuast kits use real lazer cut stainless flanges which cost over $25 each to make

This is the gentleman's tool to easily check exhausts without crawling all the way under the car




If your magnet sticks to your flange - or even worse pipe - chances are you got hosed

Please report your results

AL

 

My friends SS autochome eBay exhaust is non-magnetic so it's SS
My megan is kinda an eBay and is non-magnetic so it's SS

 

^^^nice find i learn something everyday from here!!!

 

Test the flanges - not the pipes youy may be suprized

 

the obsesion with exhausts continues.

 

does it really matter if the flanges are stainles or not
last time i check all high dollar tubular manifold still use non stainless for the flanges as well as wg flanges

 

My megan's flanges said that magnets are for the ground.

 

chances are the person will get rid of the car b4 the flanges rust off anyways. now SS has iron in it, so all SS depending on the grade will rust a little. my buschur exhaust has rust spots on it. its no biggy. my SS megan mani has rust spots on it, again no biggy.

 

My pen magnet barely stick to my flanges of my exhaust that i got off ebay

 

Yup that's iron ^^^^. It's supposed to rust.

 

The rust is on two seperate cast iron peices. good work showing me something I knew at age 5.

 

Al,

Why does it matter if they rust??? It would like 10 years to rust enough to fail.....

 

Well this is somewhat misleading anyways... there are lots and lots of stainless grades that are magnetic (400 series is very common).

Another reason some use manufactures use mild steel flanges on a stainless exhaust is because the coeffiction of thermal expansion of mild steel is less than 304 stainless. On paper it should stay sealed better Also the reason stainless is stainless is because the Chromium content when exposed to oxygen forms a layer that is impervious to "rust". However when two stainless pieces are forced together (Bolt up) it may form this rust barrier between the two components making it so when you remove them it will probably leave small galling or little dimples and things which if done enough times may start to leak. Im sure this doesnt matter but figured Id post it out anyways.

 

304SS aka 18/8 stainless has 18% chromium, 8% nickel and balance IRON + trace of (sulphur, manganese, molybdenum, carbon, silicon...................)

It will RUST unless the iron rich surface is removed thru electropolishing or passivation thru a solution of nitric acid/trace hydrofluoric acid solution.

The rust does not affect the metal property as it is self limiting - just unsightly

 

I am simply stating facts that are natural laws of the universe regarding basic materials

Magnetic quality is not a matter of debate - its a law of nature

True 300 grade stainless is not magnetic

Many exhuasts do have complete stainless constcruction and real stainless flanges - I have found two today

XS Engineering

Buschur Racing

I will add to that list as I go

I am not here to bash anyone - just to educate the community as to what you get for your $

Real stainless flanges are costly as they are difficult to machine

Look for real stainess - thick 3/8 " to 5/8 " thick even flat flanges on a quality exhuast