Guys, I have a 1.6 FMII mani/dp which I plan on fitting with a GT2860 but I would quite like to use an external wastegate. This is partly because I prefer them (synapse wastegates are baus), and partly because re-jigging the actuator so it fits on the turbo after clocking is a PITA. On the FM site, it says that “The manifold has been designed to allow fitment of an external wastegate if desired”, along with this lovely photo: is this something that people actually do? I have looked quite hard, and have never seen a single setup/photo where this has option been utilized. Is this due to design flaw or something else? It just seems unlikely that FM would design something into the manifold that didn’t really work after all the R&D they put into the thing. Thoughts?

The majority of people don't want to deal with extra plumbing (or noise if VTA), and cost of an EWG IF their internal gate is controlling boost sufficiently. Many who are running larger turbos where EWG are desired are running custom manifolds and not the FM w/EWG port.

What Frank said: most running the fm log aren't going with a turbo big enough to need ewg. CAN you do it? Yes, probably. The begi s4 or whatever has the ewg welded onto the casting, so I guess you can do the same here. I wouldn't really do that though.

I don't think you would weld anything to the FM manifold to make it 2-bolt EWG compatible. The "FM" logo pad area on top gets machined flat and the holes drilled, that's all. Should be pretty simple and cheap to blockoff with a plate if you want to go back or sell it.

Interesting. And makes perfect sense, didn't even think of it like that before.

Tim, that is great idea. I just might be doing that.
I wonder how much of a ---- it is to tap a cast manifold?

It won't be difficult.

I was assuming it was as simple as that tbh. I was more interested in whether or not it was due to cracking issues etc. I had no intention of welding flanges on, because ---- welding cast iron. flatting and drilling was how I was looking to approach it.

If it really is just down to the time and effort making it fit, then I may just do it.

IMO drilling a few holes is less hassle than fabbing up a bracket to hold the actuator.

Give it a shot. Make sure to take and post lots of pictures.

I've actually talked to Jeremy at FM regarding an EWG option - machining the "Flyin' Miata" flat and drilling for a 2-bolt EWG is the exact design consideration used for that part of the manifold.

Did he mention any suitable sizes etc?

2 bolt 40mm should work, but it would be nice to know what FM themselves think..

if a 38 is enough on 99% of our cars/setups, then pretty much any size will be fine.

I was thinking more fit than function. But I'll get the tape measure out when I get home and see...

I tried this with the one I bought from their deal of the day. That picture you're linking (even though I can't see it) is NOT a good representation of the new manifold's space you have to work with. I learned that quick when I started measuring with my spare EWG gasket.

You will run into some space issues. My 38mm flange was going to hang off the edge of the FM "logo" area. I discussed it with a forum fabricator and it can be done, but you'll most likely have to come up with a solution to getting the flange to mate flat due to the hang off. However, the top of the manifold is amazingly thick and robust, so I'm sure you can get creative with it and not worry about cracking ever.

But, I only tried with my wastegate, and I know the new designs are all getting smaller. So you very well could have a cake walk here.

I'm under the assumption that you are working with a new manifold, so this probably won't be on topic. But, if you're working with the older manifolds, they are stupid easy to convert to EXG. There is a flat space on the bottom that FM used for their FM3 system and Begi uses it now for their S5 system

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The new fm EwG setup uses a turbine housing with it built in.
Copy and paste doesn't work on the iPad... Just google it.

My begi s5 is way different than the old begi fm manifold. It has weld els welded onto it and is the new divorced flow style with the flow diverted cast into it. It also blows to get to the wastegate. You must take the turbo off or the manifold off to get to anything on it except the vacuum fitting, and I can barely get to that....

Other than that I like it and I got a pretty good deal on it barely used.

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The new one uses the ATP hot side by the looks of it. I've already spoken to ATP and the smallest they can go is a .71 housing - which will be too big for the 1.6 motor.

It is a shame really, as I wanted one of those housings so hard. I wanted to rub my genitals on it etc.

I'll just have to see how the synapse wg I have will fit.

Because all the honeys love vband ewgs and that's the easiest way for FM to try to catch up to everyone else.

I don't know... You have to pay to play with that setup.... One advantage though is I can order one today and it could be on my car in 2 days.

Maybe I am just old school but I prefer an EWG that is fed from the exhaust runners (all four) before it hits the turbine wheel and housing which could lead to 'overspeed' and a shattered turbine wheel. A set boost is achieved before the turbo via the WG and thus is controlled more accurately and another aspect that seem's to be forgotten is that most WG's can be had with different psi springs. So imho an EWG that is fed off the turbine housing is a waste of time and money and leads to more headaches especially concerning maintenance issues.

My EWG (TIAL MVR) will be v-band as I am a "Honey" and have traveled the "bloody knuckle bolt-brigade and access" to many times.

Playing devil's advocate:

What difference does it make if the wg is on the collector or another 2 inches down into the housing?

From what I've read from people who know a lot more about turbos than I do, this is an 'optimal' place for boost control - as close to the turbine as possible.