Ford Mustang Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
3,647 Posts
Discussion Starter #1 (Edited)
I am looking at two kits....One has stainless headers one has rusty looking headers....Will the Stainless eventually turn? Thanks Rob

These:



Or these:

 

·
Registered
Joined
·
4,744 Posts
Go bury some stainless in a field it will still be there 1 million years from now.
Stainless does not rust ......... ever .......... it is prone to cracking though .........
 

·
Registered
Joined
·
1,060 Posts
My Hellion kit ended up looking like this:



So I took it to a powder-coater and had them ceramic coated:



And I'm pretty sure they are stainless...
 

·
Registered
Joined
·
3,209 Posts
Go bury some stainless in a field it will still be there 1 million years from now.
Stainless does not rust ......... ever .......... it is prone to cracking though .........
Actually....they will rust. Different grades of stainless will rust to different degrees. The types used in the food industry seems to be one of the more resistant grades....but it is not suitable for headers. Stock 5.0 mustang headers are actuall stainless (409 I believe), and you know what those look like after a few years. 304 seems to be fairly resistant too...but it is not suitable for tubo applications and cannot take the heat cycles.

As for hellion, I do believe they use coated mild steel on all of their kit's.
 

·
Registered
Joined
·
3,209 Posts
If I am not mistaken my friends car has 304 SS headers and been on there for over a decade with no cracking issues but it also is not shiny and never was. It is not rusted like the 409 stuff gets. 321 seems to keep its shine once polished but it is so dang pricey.
Is it turbo’d? Is it a weekend warrior or a daily driver?
 

·
Moderator
Joined
·
4,305 Posts
Turbo charged and a daily driver. More I think of it 304 is what TTI uses for all of their Fox and SN95 turbo kits. It is also what Turbo Engineering used in their kits. I know of a lot of daily driven cars with those kits and daily driven with the turbo kits on them for 5-15 years and no cracking issues. Now Cartech kits that used 304 for years, those had cracking issues but most people long since decided that was due to a design issue causing hot spots as well as when Corky owned the place many say he was cheap and used the wrong filler rods and so forth.
 

·
Registered
Joined
·
3,209 Posts
Turbo charged and a daily driver. More I think of it 304 is what TTI uses for all of their Fox and SN95 turbo kits. It is also what Turbo Engineering used in their kits. I know of a lot of daily driven cars with those kits and daily driven with the turbo kits on them for 5-15 years and no cracking issues. Now Cartech kits that used 304 for years, those had cracking issues but most people long since decided that was due to a design issue causing hot spots as well as when Corky owned the place many say he was cheap and used the wrong filler rods and so forth.
Does TTI use headers or manifolds for their kits? I can understand that some may hold up better than others, but with the thermal expansion properties of 304...it's tough to get the welds to hold regardless of filler (especially when it's required to support a heavy turbo). If by chance they are using thick walled manifolds or weld-els, then supporting the turbo becomes far easier...and far less strenuous on the welds.

I'd venture to say that the lessons learned with those kit's are likely why a vast majority of all major turbo kit manufacturers only seem to use mild steel with their turbo headers. The longer they stay open, the more warranty issues they will inherently have.
 

·
Moderator
Joined
·
4,305 Posts
TTI has been making turbo kits longer than most of the current companies have all been in business, if you were to combine all of their years that is. The guy who started TTI came from Turbo Engineering, so he probably has more experience than most out there. Most newer companies use mild steel because it is cheaper and they see no added benefit to going with stainless. They will say stainless will crack and that is why they do not use it just like 10+ years ago places like Cartech would say they use stainless and charge more because mild steel will crack, but the reality of it was probably more along the lines of a crap design and different materials used to try and hide that. Most major automotive manufacturers use manifolds or SS headers for their turbo apps and tends to be 409 SS, wonder why they would use a more expensive material and one that costs more to assemble over MS. Now some of those SS headers by auto makers cracked such as the GN or maybe it was on the TTA but that also was discovered to be a design flaw.

TTI uses headers, some kits use a log style header and others tubular. They have mild steel flanges if I remember correctly and the tubing is 304.

One can on and on about the scientific reasons of why something just is right or wrong but I like to go off real world examples and I know a ton of real world examples where 304 is and has been doing just fine.
 

·
Registered
Joined
·
3,209 Posts
TTI has been making turbo kits longer than most of the current companies have all been in business, if you were to combine all of their years that is. The guy who started TTI came from Turbo Engineering, so he probably has more experience than most out there. Most newer companies use mild steel because it is cheaper and they see no added benefit to going with stainless. They will say stainless will crack and that is why they do not use it just like 10+ years ago places like Cartech would say they use stainless and charge more because mild steel will crack, but the reality of it was probably more along the lines of a crap design and different materials used to try and hide that. Most major automotive manufacturers use manifolds or SS headers for their turbo apps and tends to be 409 SS, wonder why they would use a more expensive material and one that costs more to assemble over MS. Now some of those SS headers by auto makers cracked such as the GN or maybe it was on the TTA but that also was discovered to be a design flaw.

TTI uses headers, some kits use a log style header and others tubular. They have mild steel flanges if I remember correctly and the tubing is 304.

One can on and on about the scientific reasons of why something just is right or wrong but I like to go off real world examples and I know a ton of real world examples where 304 is and has been doing just fine.
409 stainless contains much more iron, is more ductile and does not expand and contract at the rate 304 does. Yes, it's cheaper than 304...but it would be much better suited for turbo applications for this very reason. They also have a great deal more involved with warranty issues...which is most likely why they are using 409 rather than 304.

I'm not saying that all stainless is prone to cracking, but if you are running tubular headers supporting a larger framed turbo...then you better have some major gussets, use thick weld-el style bends or run manifold or log design. Looking at tti's kit's...it appears this is exactly what they do. I don't believe I see a kit designed that uses a tubular header design that directly supports the turbo.

Here is some info on the subject from Burns stainless.... http://www.burnsstainless.com/TechArticles/Stainless_article/stainless_article.html
 

·
Moderator
Joined
·
4,305 Posts
TTI does do it on their race kits which a lot of people run on the street. The old T/E kit was even worse in that it ran the turbo(s) under the front frame rails, worse in that it put the weight more out there with less support. The TTI single turbo race kit which is one of their biggest sellers lacks a support and does not use els or at least all the ones I have seen in person did not.
 

·
Registered
Joined
·
3,209 Posts
TTI does do it on their race kits which a lot of people run on the street. The old T/E kit was even worse in that it ran the turbo(s) under the front frame rails, worse in that it put the weight more out there with less support. The TTI single turbo race kit which is one of their biggest sellers lacks a support and does not use els or at least all the ones I have seen in person did not.
I'd venture to say that the race kit's were never designed to be daily driven....and that most are purely a weekend warrior setup. The ones that seem to be more oriented towards daily drivers are either a log design or an actual cast iron manifold. Yes, there will always be those that push the limits of the design...but I doubt he race kit's were built to withstand the rigors of a daily driver.
 

·
Registered
Joined
·
2,098 Posts
Stainless Steel

409 is a titanium stabilised ferritic stainless steel. Although regarded as a general-purpose chromium stainless steel the primary application for Grade 409 is automotive exhaust systems. Its applications are those where appearance is a secondary consideration to mechanical properties and corrosion resistance and where some weldability is required.

More highly stabilised versions of 409 are useful where 409 has been proven marginal - these grades S40910, S40920 and S40930 are stabilised with titanium, niobium or both titanium and niobium.


Corrosion Resistance
Grade 409 resists atmospheric and exhaust gas corrosion. A light surface rust will form in most atmospheres; this rust retards further corrosion but makes the surface undesirable for decorative applications. The corrosion resistance is about the same as that of 3CR12 and the 12% chromium martensitic grades such as 410, and inferior to the 17% chromium grade 430.

Heat Resistance
Generally 409 is classified as resistant to scaling in intermittent service up to 815°C and up to 675°C in continuous service, but these temperatures are dependent upon the exact service environment.

Heat Treatment
Annealing - heat to 790-900°C and air cool. This grade cannot be hardened by thermal treatment.
 

·
Registered
Joined
·
2,098 Posts
321

Background
Grades 321 and 347 are the basic austenitic 18/8 steel (Grade 304) stabilised by Titanium (321) or Niobium (347) additions. These grades are used because they are not sensitive to intergranular corrosion after heating within the carbide precipitation range of 425-850°C. Grade 321 is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.

Grade 321H is a modification of 321 with a higher carbon content, to provide improved high temperature strength.

A limitation with 321 is that titanium does not transfer well across a high temperature arc, so is not recommended as a welding consumable. In this case grade 347 is preferred - the niobium performs the same carbide stabilisation task but can be transferred across a welding arc. Grade 347 is therefore the standard consumable for welding 321. Grade 347 is only occasionally used as parent plate material.

Like other austenitic grades, 321 and 347 have excellent forming and welding characteristics, are readily brake or roll formed and have outstanding welding characteristics. Post-weld annealing is not required. They also have excellent toughness, even down to cryogenic temperatures. Grade 321 does not polish well, so is not recommended for decorative applications.

Grade 304L is more readily available in most product forms, and so is generally used in preference to 321 if the requirement is simply for resistance to intergranular corrosion after welding. However 304L has lower hot strength than 321 and so is not the best choice if the requirement is resistance to an operating environment over about 500°C.

Corrosion Resistance
Equivalent to Grade 304 in the annealed condition, and superior if a weldment in these grades has not been post-weld annealed or if the application involves service in the 425-900°C range. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60°C. Considered resistant to potable water with up to about 200mg/L chlorides at ambient temperatures, reducing to about 150mg/L at 60°C.

Heat Resistance
Good oxidation resistance in intermittent service to 900°C and in continuous service to 925°C. These grades perform well in the 425-900°C range, and particularly where subsequent aqueous corrosive conditions are present. 321H has higher hot strength, and is particularly suitable for high temperature structural applications.
 

·
Registered
Joined
·
10,681 Posts
they just turn a little bit brown..... doesnt rust that much.


stainless CAN rust its just really hard to do it.
 
1 - 15 of 15 Posts
Top