Building a custom manifold
 

For anybody that built there own did you use "butt weld" pipe. I'm looking into using 45' and 90's short and long radius butt weld pipe for the project. I'm going to do all the fabrication myself ( I am a welder, lol). It will be for a s4 13bt. Need some material advise on what has worked.

What kind of manifold are you building? Exhaust or Intake?

Since you are a welder, you should know this. But for the benefit of everyone else:

There are two kinds of SCH pipe relevant here; beveled and butt (or flat, or whatever you want to call it).

Beveled pipe is most common and what you probably want to use as it saves some work and offers better weld penetration. But then there's no reason why you couldn't just grind a bevel into a flat piece of pipe.

If you are using steel, then you will want SCH40. If stainless, then SCH 10 is fine.

Here's the making of my manifold. Start at this link and just keep going to "next page" to read through the whole thing.
http://www.aaroncake.net/rx-7/projec...jun52007-1.htm

Here is SDS EFI's tutorial on making a turbo header:
http://www.sdsefi.com/techheader.htm

Mcmaster Carr sells them and so does Grainger. grainger is much cheaper either the beveled or butt weld works fine im building mine out of sch 40 SS, the only thing i have heard people take about is back purging, i plan on welding mine and using nitrogen as a back purge set to like 5-8 psi, basically just keeps the insides alot cleaner.

--joe

Any one willing to make another exhaust mani for the s4 TII and sell it? I want one but I dont want to buy a 2300 dollar turbo setup, stock turbo is good enough. LMK how soon and how much.

The stock manifold fits the stock turbo just fine. The minor advantage of using a tubular manifold on such a small turbo would not be worth the effort.

Yeah I've been looking through the mcmaster catalog and noticed the steel butt weld comes in sch. 40 or 80. I believe the 80 has more carbon in it. Would either work for the manifold?

Butt weld is beveled if you did not know that aaron. It has beveled ends to allow for good penetration when welded.

SCH 80 is just super thick. There's no reason to use it on an exhaust manifold. SCH 40 is about 1/4" thick, and that's plenty. If you are using stainless, then use SCH 10.

Weld pipe fittings are available with and without bevels. Around here, fittings without bevels are called "butt" or "flat".

so a tubular maifold isnt worth it huh...haha damn i was going to do that, but im fine with my stock turbo , well for now,....everyone reaches a point where they want more power. Guess it would be just for looks.