Yeah this is an excellent thread. I got a dumb question though, I'm about to buy the raw tubing for my mani and I'm not sure what I should get.

Weir-tech sells the mild steel flange but stainless elbows. Will it cause problems to weld two different types like this? Should I source mild steel elbows from somewhere else?

 

Are you building a mani for 1.6 or 1.8? Either way, the cheapest places I have found high quality mild or stainless bends is here: Welcome - Ace Stainless Supply. Treadstone performance has cheaper stainless bends but honestly they are crappy quality in comparison.

To answer your question though, it will not be bad at all to weld mild to stainless bends if that is the route you choose to go. Some people go this route since the Mild flange won't warp as much when welding, and it is a little cheaper.

Also, I have 1/2 inch thick stainless flanges for sale that are high quality waterjet.

 

Just go down to the local commercial plumbing supply house and get some "schedule 40 cast steel el's and tee's" In this picture, the cast steel el's are on the right in the middle the way would would buy them. A couple of them are welded together on the middle left. And a log manifold made of tee's and el's in the back...all mild steel.

 

It's for a 1.8. Do you have a link to the right bends and Ts on acestainless? I'm not having luck finding the right ones.

 

Here is a link to the mild bends, the top two are the ones you will be interested in. SCH. 40 1.5 inch, short and long radius.
Schedule 40 - Mild Steel - 90° Elbows ("Weld Els") - Butt-Weld Fittings - Ace Stainless Supply

Here is the link to the stainless bends:
Schedule 40 - 304L - 90° Elbows ("Weld Els") - Butt-Weld Fittings - Ace Stainless Supply

As you can see, the long radius bends are a lot cheaper, only 6 bucks for the stainless, but the short radius bends are a lot more, especially for stainless at 23 bucks.

 

Sweet thank you for the links. I guess I'll just go with long radius bends since they match the Ts unless there's a reason not to. Does stainless elbows and mild flanges sound like a good combo for longevity?

 

Yep that sounds fine. I honestly don't think anyone here has ever seen a tubular or weld-el manifold fail from material other than the ebay stuff. What will ultimately determine the longevity of the manifold is the weld strength. Practice on your left over weld els, get your welder set up correctly, and make sure you are getting good penetration. If you are tigging it, make sure to spend the extra time to get good fitment on all the connections, it makes it soooo much easier to have a consistent bead.

IF YOU ARE TRACKING THE MANIFOLD, look at the absurflow manifolds as well as the updates I had to make to Soviet's manifold later in the thread, and add gussets exactly like those over the weld connections.

 

The only caveat for welding mild to stainless is to use the right filler material. Other than that, it works just great.

 

Going to keep my eye on this thread. I need a new project once I get a gas bottle. Anyone consider reusing the factory manifold flange instead of buying new? I've got a spare 1.8 factory manifold sitting around to toy with for the time being. Strangely, as you guys have found too, I have numerous pipe suppliers local, but the prices look significantly lower online.

 

The stock flange will likely end up too thin once it warps and you have to machine it flat again.

 

I say toy with it.
If properly supported during welding the flange should not warp. I made a few like this that did not need machining.
A second manifold (if you have one) is a good backing plate as it can be easily secured with 9 bolts and is stout enough to prevent warping. (Stainless flanges probably tend to warp more when welding than the stock ones.)
Removing the existing weld beads from the exhaust ports can be a pain. The best way I found to do this was using a hammer and chisel.

 

So in that picture I am pretty sure I could weld decently enough to make the log manifold in the background. It would not look pretty, but be functional. My next question is how do you cut the hole to add on the t25 turbo flange? I am at a complete loss of how that would be done.

 

You use an endmill on a bridgeport.

 

What is an endmill on a bridgeport? I honestly have absolutely no idea.

 

Bridgeport


Endmill

 

So then how do I do it, when I do not own a bridgeport and those look very expensive. I think an endmill might be buy-able.

Is it something I can do in my garage with minimal investment? or will i have to keep taking log manifolds up to my machine shop to do that part?

 

Do you have a drill press? If I didnt have a milling machine I would be considering clamping it in a drill press and using the biggest Bi-Metal hole saw I could to rough out the most of it and die grind out the rest. I would also be shitting my pants the entire time I was drilling for fear of death or dismemberment.

Or rough it out with the ox-acetaline torch and clean with die grinder.

 

I do not have a drill press. Up until a month ago I did not even have a work bench in my garage. So my tool collection at this time is very sparse.

Would a plasma cutter work? One of those is definitely on to buy list in the spring.

 

The cost of the endmill will be about 30-40 bucks, you might be able to get about the same cost at a shop to do it so i'd say thats a better option.

That would be the best method however i'm guessing if you went this route you wanted cheap anyways?

You can try using a regular drill, drill it up and then use a small grinding wheel on a drill or a dremel smooth it out. I will warn this will take a long time.



Wait is the flange threaded or are you going to need bolt/nut clearance?

If yes then you might be able to get away with simple straight cuts and putting the flange in the manifold.

 

Do that ^^^ with this:



Then clean it up with files and/or a Dremel with small cutting burs <-- a spiral flute design will be the friendliest.