Turbo headers: mild steel or stainless

[chicane67]

Uhhh. You did just say squirrel headers, ..... Id say stainless 304 at a minimum, if not 321, or at least just for the flanges themselves.

Or if you really up to it how about inconel ??

You will dis-color Jet-Hot or Olympic or any other ceramic coating with the use of squirrels, just from the saturation temperature under moderate boost.

[Ralph LoGrasso]

Uhhh. You did just say squirrel headers, ..... Id say stainless 304 at a minimum, if not 321, or at leastr for the flanges themselves.

Or if you really up to it how about inconel ??

You will dis-color Jet-Hot or Olympic or any other ceramic coating with the use of squirrels, just from the saturation temperature under moderate boost.

Oof. Isn't inconel like $373.48 a foot these days? I'll agree with Tom on this. If you're going with Turbos, don't skimp, go with 321 stainless.

[parsonsj]

Yup. Mild steel will not make it. If in doubt, have a look at the video of the Mule's headers on a recent chassis dyno. They turned orange from the heat. I don't think anybody's header coatings can handle that.

jp

[myclone]

Oof. Isn't inconel like $373.48 a foot these days? I'll agree with Tom on this.

It aint cheap... At work we use several "muffles" (basically rectangular tubes) which are inconel that are 20'L X 8"W X 4"H and the wall thickness is about 3/8". The replacement cost is $10k each and we have 4 of them that get replaced about every two months or so.

YEEEOUCH!!!

IMO inconel is over kill for anything thats street legal 321 is your best bet if you have the extra dollars to spend but if youre pinching pennies then 304 is fine if the welds are quality work and some thought is done on tube placement to ease the expansion stress from the heat.

I built a set of turbo V6 headers from 16 guage mild steel and had them coated with the high temp (2k deg) ceramic coating and they held up fine. Of course the longest the engine stays WOT is 1/4 mile so the mild steel doesnt really get hammered continuously with high heat which IMO is why they are still alive. Next set I do will be 304 as soon as that money tree thing takes off and I can pick up a TIG welder.

My .02