There should be links the the pictures. It looks like an inverted v-band flange.

 

What kind of turbo do you have?
Cant you ask whoever you purchased it from?

 

I've always wondered what those are and how the hell you're supposed to attach your exhaust, lol.
Yes, i am an ignoramus, will be interested to hear the answer on this.

 

Weld on? I honestly have no idea.

 

It looks like they milled it off to place whichever V-Band Assembly you choose. We've done that before. You'll have to measure the Diameter, buy and weld on the size you need.

 

How do you weld to cast iron?

 

A really good, tight Tig-Welder

 

It should technically be cast steel not iron for a turbo manifold so it will have better results but in general. Preheat high nickel fill rod reheat and cool slowly. If the manifold has run for a significant time it can have more carbon in it leading to more brittleness also something to be careful about.

 

looks like the style HKS used on their early garrett single turbo kits like the T04E and S kits...it's a system of compression rings that seal ...probably common on diesel truck vehicles...seen pictures of the kits and not the most inspiring looking downpipe to turbine connections at a glance.

 

I've seen this on a couple old 930s with upgraded turbos before. On those setups the muffler and turbo are rigidly attached to the engine, so there is a "male" flange that literally just sits in that groove.

 

If you need a V-Band welded on, we do them often. 120usd Just need to ship the exhaust housing alone. john@gleasemanufacturing.com

 

Where do I get the male flange so I can have it welded onto my downpipe?

 

and what is it called?

 

[/HTML][/HTML][/PHP]I thought turbo hotsides/turbine housings were made of cast iron?

 

Not much of anything is actually made from cast iron. Cast iron is very brittle maybe some pots and pans but not car parts. Steel is mostly iron but other elements added to make the mechanical properties better increased strength and ductility etc...

 

What about cast manifolds? Are they iron or steel? And I need to know what that flange is called.

 

Most production turbo housings and manifolds of recent manufacture are D5-S Ni-resist.

 

look up truck parts supply stores in your area....take the turbine to them and they should be able to get you the male flange and ring assembly...I did that with a garrett turbine housing off a truck application with a wider v band casting on it then the norm... they ordered the matching tube flange to weld on the downpipe and v-band for me...dirt cheap also

 

Maybe try and PM user "markus1981". I may be wrong but im pretty sure he recently installed an older HKS turbo with a similar looking flange, and asked the same question re "what flange is it"

He posted a pic in his build thread, link below, and at a glance, that looks to be the same flange as in your image;
https://www.rx7club.com/build-thread...1068778/page3/

I dont think he ever came back and updated what the flange was, but I do believe he got it sorted and installed in the end (with that flange) so it mite pay to flick him a message and see what he knows.

If you do figure out what flange that is, please do post it back here. Its obviously stumped quite a few knowledgeable people as you don't yet have a solid answer.