Stupid wireless office keybaord was acting up and i couldn't find batteries lol, but yeah, i still type like **** with a college education

 

well i have been very entertained these last few pages by the "GREAT" exhaust debate. i want to thank everyone on that as its hard to find entainment while in iraq. while DB does make some nice parts( i have my eye on the v banded exhaust) just about all of the big boys have expensive ****e for sale, if they built them or not. but i also agree that posts like this dont exactly encourage me to buy parts or tunes from DB or big al, threads like this want me to take my hard earned deployment money and go elsewhere.

in closeing i do want to say the "the china bashing racist" quote made me laugh for about five minutes, thanks

 

That is done for a reason and they are usually cold rolled steel. The CTE is much lower for cold rolled than it is for stainless, about half. This helps to eliminate the elongation of the flanges that can break exhaust studs.

 

Not always true and please don't bother with a debate. Case in point, I use 347 rod when I weld 321SS headers and more often than not the rod acts like a typical ferrous metal. Yes, a magnet will stick to the 347SS rod. Just because a magnet sticks to the flange doesn't mean it isn't some 300 series grade of stainless.

 

This test was one of the first things I did to my tbe from SSAC that I bought over 2 years ago. I was surprised to find it was SS for that price.

These exhaust threads are becoming pretty rediculous.

 

Just by way of clarification - I am no racist

I am not bashing China per say

If our society at large has really gotten to the point that expressing the view that made goods are superior is such a controversial view point then I think we are all in big trouble

The main trust of the thread was to show how people can cheaply test exhuasts with a magnet to gain some insight into how they are made

 

I did a quick search to see if I could find a site to add some clarity to this issue.


=============================
http://www.azom.com/details.asp?ArticleID=1140

Background

Magnetic permeability is the ability of a material to carry magnetism, indicated by the degree to which it is attracted to a magnet. All stainless steels, with the exception of the austenitic group, are strongly attracted to a magnet.

Austenitic Grades
All austenitic grades have very low magnetic permeabilities and hence show almost no response to a magnet when in the annealed condition; the situation is, however, far less clear when these steels have been cold worked by wire drawing, rolling or even centreless grinding, shot blasting or heavy polishing. After substantial cold working Grade 304 may exhibit quite strong response to a magnet, whereas Grades 310 and 316 will in most instances still be almost totally non-responsive.

The change in magnetic response is due to atomic lattice straining and formation of martensite. In general, the higher the nickel to chromium ratio the more stable is the austenitic structure and the less magnetic response that will be induced by cold work. Magnetic response can therefore be used as a method for sorting grades of stainless steel, but considerable caution needs to be exercised.

Stress Relieving
Any austenitic (300 series) stainless steel which has developed magnetic response due to cold work can be returned to a non-magnetic condition by stress relieving. In general this can be readily achieved by briefly heating to approximately 700 - 800°C (this can be conveniently carried out by careful use of an oxy-acetylene torch). Note, however, unless the steel is a stabilised grade it could become sensitised to carbide precipitation. Full solution treatment at 1000 - 1150°C will remove all magnetic response without danger of reduced corrosion resistance due to carbides.

If magnetic permeability is a factor of design or is incorporated into a specification, this should be clearly indicated when purchasing the stainless steel from a supplier.

Cold Working
Many cold drawn and/or polished bars have a noticeable amount of magnetism as a result of the previous cold work. This is particularly the case with grades 304 and 303, and much less so for the higher nickel grades such as 310 and 316. Even within the chemical limitations of a single standard analysis range there can be a pronounced variation in the rate of inducement of magnetic response from cold work.

Magnetically Soft Stainless Steels
In some applications there is a requirement for a steel to be "magnetically soft". This is often required for solenoid shafts, where it is necessary for the plunger to respond efficiently to the magnetic field from the surrounding coil when the current is switched on, but when the current is switched off the magnetic field induced in the steel must quickly collapse, allowing the plunger to return to its original position. Steels which behave in this way are said to be magnetically soft. For corrosion resisting applications there are ferritic stainless steels which are magnetically soft, usually variants of a grade "18/2" (18% chromium and 2% molybdenum) but with very tightly controlled additions of silicon and often with sulphur added to make them free machining. Special mill processing guarantees the magnetic properties of the steels.



Source: Atlas Steels Australia

 

Closed for cleaning.

Thank you,
mitsuorder

 

The bickering was taken out of this thread. Keep it on topic and quit acting like a bunch of defensive children.

 

My friend has a Buschur exhasut and his is rusting already. Its just a little surface rust but rust is rust. Not to mention that the exhasut came with like 5-6 small dents in it.

 

My Evo has always been a strong runner compared to others in my area..eventhough it has the Megan exhaust. The muffler on them is good..it's a true 3" through. The intire exhasut is 3" with no neckdowns. It definitely works good, fits good, sounds good, etc.

 

FYI, stainless steel can rust. My old twinturbo 240Z used Stainless intercooler pipes and they would acquire some surface rust. It turns out that only happens when using a Chinese grade of stainless.

 

All my Buschur parts are magnetic. Even my Dynoflash is magnetic. I got hosed.

 

Amen to that. That has got to be the most idiot thing a so called tuner could ever say. "cant reflash car because of a fuel pressure regulator".

Anyways I am good friends with a few welders who make turbo manifolds and custom exhausts all state that stainless is easier to weld, but harder to keep from warping once the heat is applied. Also it tends to expand more than mild steel. This is the reason why some turbo manifolds that are manufactured using stainless flanges cut the flange at the mounting holes to relieve some of the manifold stress caused by heat expansion. As far as exhaust, I have supposedly a name brand exhaust, APEXI n1 had one on my honda and bought one 2 yrs ago for my evo, and the material used for construction looks the same as it did before. (Stainless exhaust rear section, and then the midsection looks like mild steel that has been coated) Not sure if newers ones are created a lil differently. I do know I have driven thru lots of water and humidity and unpredictable changing weather in houston(one minute hot, next minute cold) and when I look under the car and wipe the dirt off the midsection it still looks as new as it did when I bought it and based on what I have seen(Stainless DC SPORT Exhaust on my 02 Acura CL) the stainless if exposed to odd weather conditions tend to accumulate some rust in some spots. I know it can probably be polished out, but who is going to do that.

 

I understand your point and have had enough of the bickering and throwing the moderator's in the middle of ludicrous discussions, vendor bias and fighting. His comments were correct and we are done with the stupid arguments. Your issue is not with the moderator's but the members and vendors who throw insults back and forth like a tennis match. It has become impossible to have any discussion on this site because of the confrontational attitudes of a few members. We are going to remove them permanently with IP bans. Post your moderation concerns in the Feedback forum. Thread closed.

Speedlimit....