btw im also an mechanical engineer

back purging only stops frosting of the metal, as stainless needs it, yes the joint will be weaker, but that doesnt have anything to do with the fact that 304 has alot of thermal expansion which will cause cracks.

but i still dont get why people worry so much of of ceramic coating flaking off, it never happened to me, nor i have ever heard anyone tell me theirs flaked off, only people speculating it could flake off, this is how urban legends start.

if in doubt call the company that coats and ask them if its going to flake off and damage your turbo.
mine only faded, never chipped or flaked.

we can only give advice its you in the end who makes the decision, so good luck

 

Doesn't suprise me I hope you didn't think I was contradicting you... I felt that we were on the same page... I was just defending both of our posts from this comment:

Since the question had nothing to do with design, and both of us gave factually correct information regarding the pertinant material properties.

Then further defending myself (since I'm more of a lurker and I took it as a stab at my credibility) from:


Because after thinking about it this morning I realized that my viewpoint had nothing to do with having built a turbo setup in the past... and many of my friends who have owned many turbo cars really wouldn't be qualified to give an accurate account of the material properties of their exhaust manifolds. My response had more to do with my knowledge of materials coupled with the first hand experience of my friends and just generally in stories I have heard over the years. Each time I have seen a failure, I just apply the theory and come up with my own conclusion... Which is exactly what I would advise anyone to do... not just take someone elses word as gold... and likewise not completely discounting someone elses philosophy on the subject. Listen to the reasoning for someone's philosophy, and then come up with your own conclusion.

 

Fabbing up a set now (twin turbo C5). Got a hell of a deal on 321. Flanges came from Stainless works. 304 I think.

 

All material will cost right about $1200-$1500 for complete 321 stainless headers. Not bad when you consider that Burns wants $1000 just for the collectors!!

 

I have done both Mild and coated and stainless, mixed with carbon.. I can really say the carbon suciks if you do not coat.. the rust just looks like crap... The piping on the truck is both and man you can tell what is stainless and what is carbon... Have not seen any cracking yet, but the turbo is total supported and its only been a couple of months...
The hole rust in the exhaust is a little weak becuas cast iron rusts and that was the old staple for oem turbo stuff...
Ricky

 

I have never fabbed up a turbo system. I am, however, an excellent and experienced fabricator. After building the motor up from a bare block, and porting the heads myself, I fabbed all the brackets, piping, layout, etc. for this:



You'll also notice that I had some information that matched the initial question. I gave him the source, the author and where to find more.

I know there's a problem with bench racing and second-hand knowledge. That's the web for you. I expect that if you could audit all the people on this forum, a percentage of them would not even own the cars in their sigs, never mind all their 'mods' and times. It's up to the reader to determine what information is of value. Is mine of any less value because I haven't built a turbo system?

Confucius says: "Even the ugliest oyster can yield a pearl" (OK, I never met Confucius, but my buddy met a guy who said he knew his doctor's grandson So I feel like I can talk with authority).

Jim

 

Thanks everyone! Like I said above, I wasn't trying to dog anyone's statements with my question. I am in the process of building my car from the ground up. I just started the chassis work a couple of weeks ago and it was going well untill I got called back to work from my vacation. That is the last time I tell them I am still going to be in town.


Thanks.


Tim

 

I think you need to go straight to the source.. Call Burns Stainless out of So Cali and talk to Casey.. He knows just about everything for headers, from boats, to planes, to Indy and beyond.. (949)631-5120