I agree on going Mild Steel, i've had my fair share of stainless junk. not even 500km onto a kit (that used North American 304SS) and the welds were cracking left right and center (a local fellow made the headers up). Now that i do my own kits I use nothing but good quality mild steel.

 

good to know sucks tho looked like a nice kit

 

High temp coated mild steel will out last the motor there bolted too...

john

 

Thanks for sharing your experience. I really hope that others see this thread. We still see a lot of people who buy these kit's even after being told not to... it's nice to have the pics and real owner experience to back it up.

This thread should be stickied...

 

just an fyi to the post above, i've also had good success mig welding cheap stainless and having it not crack, or atleast last longer lol.

 

When mine cracked I took to my uncles welding shop and teh guy that does his tig work said it was a bitch to weld back cause the metal was ranging from .045 to .050 thick. So the answer to how thick the steel is THIN

 

It's always easy to post up a success story and not so fun to post up problems. This is good information, a lot can be learned from failures. Thanks for sharing your experience.

 

Interesting and thanks for the review.

 

So when you sold it to another guy looking for a turbo kit, did you tell him how much of a pile of shit it was?

 

Yes i did.. that is why he got three headers and two crossovers. I also told him how much i paid to fix them the last time. He was sold on it when he knew it made 577rwhp on a 130k short block.

john

 

What are peoples opinion on 304 schedule 10 which has a wall thickness of .109"?

Jared

 

Thicker 304 will probably do fine... schd 10 is very thick and should be ok....

Like it's been mentioned, you're better off sticking to mild steel unless you have the cash to do it with some good 321 SS.

On a stainless kit you can expect over time to have cracks show up here and there simply because of the material properties vs mild. SS is brittle and is prone to cracking, whereas mild has some flex and forgiveness to it. I've used a few mild kits, and fabbed some mild kits and haven't had any issues. A lot has to do with the construction of the pipes too...anyone can just weld some pipe together, but if the pipes are welded together already in a tensioned state you can expect for cracks and breaks to occur. That's why you're better off spending the $ on a reputable place if you can't do the stuff correctly yourself.

 

I'm not a welder but I'll argue against the use of 321 in a turbo kit especially when applied to a drag race type situation. My customers that build turbo kits for drag radial and 10.5 outlaw cars have told us repeatedly that the 321 is far to brittle and cracks very easily especially on any car that see's tire shake. My opinion is that 321 especially 18ga is useful for N?A cars that are looking for the lighest most durable exhaust material wihout getting into inconal. I would say the best alternative would be to stick with 304 SS with a decent .065 wall thickness, use bracing and proper welding techniques. The kits that I have seen built this way have lasted several years and performed well, mild steel unless coated inside an out can have rust issues especially if race or other exotic fuel types are used. I have seen a kit that looks fine on the outside have a pile of scale and rust fall out of it, just offering my views, been around this stuff for along time, heck even my factory Turbo Buick headers cracked back in 1989.

 

+1 All 3 of my .065" wall 304 turbo systems are doing well, 5 years on one, 50k on another, no cracks or repairs. It is all in the thickness (not the grade) of the material, the welding technique, and viabration isolation (includes the brackets) used to assemble the kits. Ever wounder what filler material is used tio weld the chineese kits? :hmm:

 

i am sooooooooooooooo glad someone with first had experience took the time to break this down for me esp. you always hear the stories about things like this but to actually see the pics really makes everything else believable.

 

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.

 

go here for more info

http://www.azom.com/details.asp?ArticleID=967

 

Im with Kerrdog I wont have a mild steel kit. The last kit I had ate it self up from the inside out. It was Not coated on the inside. You could take any piece of the hot side and tap it on the ground and scale would fall out. It looked like the piping had been in the ocean. I ONLY ran 110 fuel in the car no pump gas and only drove the car once or twice a month. I believe if the piping had been heat cycled / driven more that would of help keep the rust down. In a matter of three years I had holes thru the bends and I totaly redid the whole hot side before i sold it. I would say mild steel Needs to be coated inside and out and pretty much no race fuel ran thru it. Stainless needs to be the thicker the better and i would use header wrap to help hold the heat in it or have it ceramic coated as well.

 

same headers... same problem.


I would post pic but right now its about -2*F and there is 3 ft of snow ontop of the car lol

 

304 stainless I've never had a problem with it in any of my kits. Design is key... Stainless expands in the design of the kit and where the turbo is mounted it looks to me like a crack do to stainless expansion and the fact that the turbo bracket restricted any growth thereby ending in a stress crack. Swages should have been used in the design. That is what I notice in that kit.. Problems in design.