I'm usually a form follows function kinda guy. If there is no functional difference between the two, I'll take the cheaper one.

Having said that, if you decide to go with the sand cast one don't you EVER show us what an investment cast one looks like. After what I've seen on the earlier ones (even though they explode) this is frankly a huge disappointment:

https://www.miataturbo.net/attachmen...1&d=1400727897

Switching to a sand-cast part enables us to spend a not-insignificant amount of money on ensuring that the surface finish is up to par and still substantially reduce the retail price point. It will be way nicer than BW's cast housings are.

I have a feeling even Hustlers anus on its worst day looks better than BWs current castings.

I'm in for cheap and functional its going to be covered in surface rust anyway.

+1

Cheap and functional, definitely.

part of the function crowd here. less money is more for other parts!

cheap & reliable plz!

If it is an exhaust manifold, it will look like it was sorry it was ever born after a few thousand miles anyway, so I see no reason to make it more expensive.

The BW sand cast turbine housing doesnt even look bad.

All depends on the quality of the sand cast/Foundry.

I've seen some very good ones; I've seen some awful ones. I'm partial to investment castings since the tolerances are tighter and the castings tend to be less porous on the surface. This said, exhaust manifolds get post machined so it's largely an aesthetic/cost issue.

-Zach

That was my own intuitive reaction.

Granted, you can investment-cast it out of unobtanium, and then polish it, and then apply an exotic coating to it, but at the end of the day, it's an exhaust manifold. It might be an extremely nice exhaust manifold, but you're still going to bolt a turbo to it, close the hood, and beat the shit out of it for the next few years, not buy it dinner, tell it that it looks positively radiant tonight, run your fingers through its auburn hair and make gentle, passionate love to it on 600-threadcount Egyptian cotton sheets with Al Green playing softly in the background as the flame from a single a cinnamon-scented candle casts passionate shadows against the velvet-draped wall.

This is the miata crowd. Was the choice ever going to be anything but the cheaper option? :dealwithit:

Assuming the function is the same, no and $0 respectively. If you can get equal performance from a sand cast, then I assume you have a post-process for the interior features. Sand cast makes more sense given the limited volumes of your target market. Investment casting makes sense in higher volumes and/or if you can achieve better consistency and performance. You are selling to cheap Miata owners, not the Porsche, BMW or Ferrari tax crowd ;) .

Stupid question:

I have no idea what sort of production volume is anticipated for each individual style of manifold, however I presume the production volume to be relatively low and centered around small batches.

Presupposing that the wax patterns were produced on-demand by a 3d printing process, would the decreased up-front tooling cost justify the increased per-unit cost to the point where something resembling cost parity is achieved?

You forgot synergy, leveraging and upflow.

What. Just. Happened.
:rofl::rofl::rofl:

I guess I fall somewhere in the middle.
For $50 extra, I'd buy the prettier piece.
For $150 extra, i'd rather coat the cheaper piece.

But I don't think my price scale is realistic.

I have extra dicks for sale if you want...would add value

I picture this exact scene, but with the go-kart radiator heating unit on the floor.

You don't know that :giggle:

I lol'd IRL :rofl:

So, serious question. This link was posted over in the Makerbot thread just recently: Lost PLA Casting from 3D Prints

It shows how lost-material casting is possible with PLA filament. I'm not suggesting that you guys open your own metal foundry, however it suggests that the patterns for an investment-casting process can be produced very inexpensively in small quantities. The Makerbot Replicator Z18, which costs $6,500, can construct objects up to 18" x 12" x 12" in size.

Cool looks like lost wax without the centrifuge. How the the aluminum get in all the nooks and crannies w/o centrifugal force? Gravity? Seems like there would be porosities

Thats what the risers are for.

I don't know, actually. That link is really cool.

It might be cheaper to CNC foam in small volumes. Though CNCing an exhaust manifold sounds like a pain in the ass.


-Zach

I'm not sure you'd be able to.

Remember, the pattern needs to be hollow on the inside, as it's an exact representation of what the metal piece is going to wind up being. CNCing the inside of a complex shape like a pseudo-tubular manifold would require a 5-axis machine at minimum, and greatly restrict the internal geometry of the part.

Totally agree ... difficult or impossible (I hinted at this, didn't I?)

5 axis isn't always expensive. I work for a med-dev group and we have a small (but competent) connection with a 5-axis in his VT basement. Complex design surfacing parts cheap cheap cheap out of moderated expensive materials such as renshape.

FDM wax seems to make economic sense for jewelers. Large parts are still relatively pricey.

True, but now that it's possible to use PLA filament squirted from a consumer-grade machine for large, coarse parts which will be subjected to finish-machining on critical surfaces (like exhaust manifolds), this changes the rules.


Serious idea. Design the manifold, and then split the design in half between 2 and 3, and right down the middle of the turbine flange. Print the two halves on a cheap machine. Construct a fixture to hold them in alignment as they are glued together. Use the glued-together piece as the investment pattern.

And that PLA stuff can just be smoothed out with bondo. Or some other filler. Fill in the groove and just keep it flush with the ridges with a straight edge.

I was at the Maker Faire in San Mateo last weekend and I was in awe of the sheer number of vendors putting out 3D printers. And all the other cool stuff:

Maker Faire Bay Area 2014 photo recap | EDN

Only 600 threadcount? I thought this was America.

All the cool kids are machining the casting sand directly...

http://www.mmsonline.com/articles/straight-to-sand

I actually applaud your first post as timely and appropriate, even though it wasn't in the"meet and greet" section. Usually that's a problem but not this time.

Every time this thread gets posted in I think the kit has been released lol. What's the deal with it? Is it still in production? This was the whole reason I went EFR in the first place lol

Talking to foundries about the project right now. Talking to the shop I'm most excited about working with tomorrow morning, in fact. I will release manifold renderings and pricing when the supplier and ETA are finalized.

So will it be EFR 6258/6758 based? I understand if you don't want to make official promises or statements yet, just wondering. Based on your radiator that I have I can only assume the turbo kit will be just as refined and of high quality. Can't await to see this take off!

B1 frame, yes (6258/6758/7163).

The really cool kids are casting their own bananas.

Sand Cast Banana for Scale is So Metal | Hackaday

Is the manifold a log or tubular? Juicy details plz!

4-1 cast tubular.

I can't wait to see some pictures. I am honestly very interested where you are fitting an EFR to still be AC/PS compatible.

I think I know of a couple ways it will fit, it'll be interesting to see what they do. Since they all have some pretty different downsides (intake or downpipe restriction, or pushing the limit of the angles the bearing will take). She's a big bitch when trying to put it into the engine bay when you think of how small of a turbo it really is.

A top or even side mount should fit the EFR and let you keep ac and ps. The harder part then is IC pipe routing, especially on NA cars that have the popups

On a more serious note, what is the advantage of machining sand versus doing a lost-plastic process with an FDM positive? Seems to me that the latter would be faster, less labor-intensive, and allow for more complex geometries.

Andrew,

Any recent updates: I thought you had a go with Foundry and we could be looking forward to track-built Miata turbo system.

FYI: today I watched Marc Hoover in T1 at Laguna, quiet an impressive performance by Turbo Miata.
It inspired me.

😂😂😂😂

Lots of progress, but nothing I am interested in discussing publicly. If you are meant to know more details at this point, you already do. I will have more information for the general public when the production samples arrive in a couple of months.

Do you know how bad I wanted to edit your posts and make it say that the kit is ready for shipping?

Probably as bad as I wanted to make it say the kit was ready except he was still working on good sourcing for Inconel nuts.
What good is life if you can't have a little fun?

I lol'd IRL

This SLA has been sitting in my office for a few months now taunting me. I haven't talked about it because so much of the process has been up in the air, but the big stuff and a lot of the little stuff has been nailed down now. The foundry is chosen, meetings held, the PO is issued, and the (really scary big) check has been cut.

The only question left to ask is this: Who wants one?

• Designed to fit the Borg Warner EFR B1-frame turbocharger family (6258, 6758, and 7163)
• 3D modeled from bare flange locations
• Shell mold sand cast - similar resolution to an investment casting at about 1/3 the cost
• Cast and post-machined in the United States
• 347 stainless steel
• 4 into 1 tubular-style. Computer modeling during design has the "blend point" of the four runners beyond the end of the outlet flange
• Unequal length, but small volume. The focus here is on response over ultimate power
• T25 outlet lets us use the small-A/R EFR turbine housings and keeps cost down. With Inconel studs, flanged joints are stone reliable

This isn't a 100% final part, but it's basically there. There are some wrench relief cuts that aren't shown here, but the fundamenal shape is what you will get out of the box. I am approximately 6 months from shipping production manifolds. I should have a single working sample in about half that time. Foundries work s-l-o-w-l-y.

There will be an initial group buy for those of you who are interested in helping me capitalize the 5-figure mold and 5-figure initial purchase order in exchange for a discount on the manifold and a sizeable discount on a turbocharger to go along with it. The manifold will be sub-$500 for this group buy. I'll announce more details about that part of the process in the next week or two. We will, of course, bundle a downpipe with the manifold/turbo, but I don't have any details to share on that. Needless to say, it's getting a similar level of attention to detail as what's been put into the manifold project.

Attachment 237793

Attachment 237794

Yep. I've been waiting for this.

:party:

https://www.miataturbo.net/attachmen...ine=1431053909

FINALLY!!!!!!!!!!!!!

:party:

Very nice Andrew, good job.

I never thought I'd see the day. Welp, I'm in for a mani/turbo/downpipe.

Wow, congrats andrew. New brakes and new manifold announced in the same week? Looks like a lot of hard work is finally coming together.

Where do I sign up for the 1.6 version.

kidding

Oh man, that is exactly what I wanted to weld up back when I first started down this rabbit hole. I'm guessing fully fabricated downpipe?

I'm local and already have an EFR, built motor, MS3 and EV14s plus you already knkw im really I'm good at breaking shit. Let me know when I can buy one. If I can't break it you know it'll be golden. :party:

Glorious update, I can't wait to see one in person!

Very nice! Unfortunately I gave up waiting, but that does look neat!

:drool:

Much manifold, many efr, DO WANT. :bigtu:

Bump. Any updates?
















Kidding! Kidding! Kidding!