If you could choose to make a turbo manifold out of the following two options, which would you choose and why?

1 - Mild flanges, ss runners, uncoated
2 - Mild flanges, mild runners, coated

 

Maybe I am speaking for myself here. But I hope not, I only use SS in my pieces. Everything down to the last flange, v-band parts, bung, tab, filler, bolt on a support, whatever.

I don't like dissimilar metals. If it can be avoided why not? Im not saying the other ways are wrong by any means, but that is how I do it and I know many others are the same.

People often use mild for cost. Many use it everywhere and on a car thats ran frequently have no corrosion issues. Coating obviously does help. If you chose to mix and match, make sure you are using the right rod in the right places.

 

mild flange. ss runners.

mild flanges because they dont like to warp as much and like you said thermal expansion; and ss runners because cracks usually are more likely to develope there.

 

Snow Trooper - What thickness are you using for your flanges? I have seen a few stainless head flanges warp and shear head studs when subjected to high temps. I also agree with you about mixing two different types of metals, my main thought is if a mild steel head flange is used because it has minimal thermal expansion then wouldn't that subject the manifold to increased pressure where the stainless runners are welded to the mild steel head flange?

Do Full Race use mild or ss head flanges?

In for more info. Would be great to hear more about who uses what on their manifolds?

 

op revised