EWG on cast FM manifold?
 

I have been accumulating parts for my next setup. Currently my car has a SR20 turbo, bolted to a Flyin Miata cast manifold. Bolted to my turbine, is a Flyin Miata cast turbine outlet. I bought a SS 5 bolt flange, and a piece of 3" SS 120* mandrel bent exhaust tubing so I can fab up my own outlet. My turbo is currently internally wastegated, but I'd love to run an external wastegate. This exact wastegate, in fact:
NEW! Tial External Wastegate, V-banded 38mm (aka V38 aka MVS 38mm) : atpturbo.com
Tial 38mm V band.
I remember reading about grinding the "Powered by Flyin Miata" lettering off, and drilling and tapping for a 2 bolt flange on the manifold. I used the dimensions for that flange as found here:
http://www.tialmedia.com/documents/w3_tial_38_dim.pdf
and I drew it up on a piece of paper and laid it on my manifold. No dice...see photos:
Attachment 68857

Attachment 68858
I'm thinking, "now what?" What if I modified the oval shaped 2 bolt flange and made it round? It would fit like this:
Attachment 68859
Perhaps I could weld it to the manifold? The manifold is cast though, so I'm not sure how well that would work.
What if I tapped 4 holes in it and bolted the round flange to the manifold? like this:
Attachment 68860
Who has done what I want to do? Which one of my ideas do you think would work the best?
I welcome any good input on this.
Thanks guys.

patsmx5 did exactly that.
I'm sure others did that too.
Why spend all that money on a ewg just to tack it to a log?
Also there's a very good chance it will crack. Even the begi s5 pieces, professionally welded and whatnot, tend to crack in that specific spot, because cast iron doesn't like to be mated to a tube or a flange.

good luck. I think its pointless. Sell the log and buy a proper tubular manifold with ewg from abe for just a couple hundo more, and enjoy ALL the benefits of a setup like that. Just my .02

Thanks Vlad. I had a laugh cause its 1:00am where I live, I posted that and thought, "I wonder who will be the first to respond?" I actually said to myself, "probably 18psi."
I'm thinking it would be a real bad idea to weld on that manifold. What's your opinion of my 4 bolt flange design? I can't see how bolting a flange on would cause problems.

I can't find any evidence of this. I'm looking for pics/ etc., anyone have a link?

check this out. tacotaco manifold with a tial ewg

Mazda Miata Turbo | Tial MVS 38mm External Wastegate Install

The problem is not welding cast (they have rod and procedure for that) but welding cast to mild steel. You'd be better off bolting it on if you were to do that.

I'm not sure what 4 bolt flange design you're talking about.
search his name: patsmx5. He's been banned for years, but I often still talk to him. Very cool/knowledgeable guy and successfully implemented quite a few interesting/different ways doing up a turbo miata.

Thanks for the link. That actually looks decent, although, I'm going to do the bolt on method for mine. I don't trust mating SS to cast.
Dude, that link was perfect...same WG as I want to use and all!

glad i could help! ive been thinking about doing this for a while now, but i dont want it to crack as others have stated. i know that manifold has been parted and sold, maybe you could contact that current owner and see how it's holding up

The one in my last photo in post #1...it's round with the 4 X's around it. That was my paper drawing of my "I could make this flange" design.

I searched his name and found like 149 posts from him. If I remember right, wasn't he the guy that ran MS2 on a '99 N/A with nitrous and went like 14.0? I never followed him and a turbo setup...

Yep, rand a 100shot of nitrous. Then built a gt32 setup with a begi log and ewg.

The flange might work. I'd probably take that route over welding too

Bit more info here:

https://www.miataturbo.net/diy-turbo...anifold-66958/

still no conclusion though.

4 bolt flange would be a good idea, weld the MVS supplied inlet flange to the 4 bolt flange.

That's the plan! I gotta check the metal rack at work and see what I can heist to build this flange.

Wow, I just got angry reading that thread again. I had to yell at you a lot and you still didn't listen.

For the last time- a 2bolt WILL NOT work over the "FM" logo on the new manifolds. THERE IS OVER HANG AND IT WILL NOT SEAL!!!!!!!!!!!

THIS PICTURE IS A RENDERING AND IT NEVER HAPPENED. THIS WILL NOT WORK ON THEIR CURRENT PRODUCTION MANIFOLDS.
https://www.miataturbo.net/attachmen...ine=1342105981

OP, PatsMX5 welded it on the BOTTOM off the collector.

Also OP, you have a T25, do this
https://www.miataturbo.net/attachmen...ine=1342086382

OP, I love you and Imma let you finish, but that turbine replacement is the belt solution at this. AT THIS TIME.

No its not. Its mediocre. Best solution is a custom tubi with ewg from Abe :party:

PS: to clarify, I know many use this "solution", but if you're letting the gasses into the hotside before venting them, you're still choking up quite a bit, and its more of a compromise between iwg and ewg, not a "true" ewg. It will probably not creep like iwg though so at least that's good.

Agreed. That's why I sold mine :greddy:

But if OP wants to hack his cast manifold, then I don't see him really looking to spend baller bucks on a new hotside.

you know what's easier?

Lulz. I gave up and sold it In the end. going artech instead :party:

Rofl. Me too. Abe is doing some work for me right now :vash2:

Being a MOD. Having a stock everything. Being afraid to leave your house.

Yo, on tha real, MS3x