Well yes, but also large automotive company OEM quality welds.

You guys would probably laugh at most of the welds on our Grand AM cars, and all the zip-ties, they would make you laugh too...

Well, honestly, it's a bit difficult to tell from some fuzzy pictures on the interwebs but as far as I can tell it has failed right at the edge of the weld. My guess is that either there is some geometric affect (ie undercut causing a high stress concentration) or some softening in the HAZ. Or possibly, some combination of both. Again, this is a complete guess based on your pictures alone, I'm probably completely wrong.

If you want, you can send me the manifold and I can do a complete failure analysis with a hardness cross section of the weld, microstructure analysis of the weld, HAZ and base metal, and maybe even some SEM work... all of this would be destructive analysis though so the flange area would need to be...uhhh...re-done. It sounds like you've already sent it back to be repaired so maybe it's a bit late for that.

I think I said this before, I'm not saying that your NOT overloading or overstressing the flange/manifold. What I'm saying is that if the weld met the specifications I work with, and the part is overloaded, it would fail further up the runners in the base metal just outside of the HAZ. Your part didn't fail there so it's hard to say if it failed because of the loading/use condition or because of a "bad" weld...

 

Its not surprising that it failed in the heat effected zone. That's where a welded and non-treated part is expected to break. Normally if a weld breaks at the weld it was a bad weld, if it breaks in the haz it should have been stress-relieved/annealed/normalized, or at least that's how I see it.

 

It didn't fail in the heat affected zone. It failed in the weld itself. And exotic materials are the obvious solution here.


Basalt fiber sleeve reinforced ceramics and super alloys should fix this up just fine.

 

Thats right on the boarder of the heat effected zone. If that is a weld failure its only because the gap was too large and there was not enough over lap of the bead.

Actually, looking again, it broke exactly along the edge of the bead. Not enough penetration on the tube side of the bead?

 

Pictures of the inside?

 

here's mine, at the exact same spot, i even lost a little piece of weld in the meantime

 

Those just look like super bad welds. ^

 

In for 'penetration' pics


My ARTech DP/exhaust has good penetration (for the size of the ... weld )

-Zach

 

lol HOW IS BABBY FORMED

You had me at microstructure analysis. Thank you, but the manifold should be in Abe's hands in a few days. He is going to pull out all the stops for it and gusset the everliving fucky out of it and also add a crane.

I am going to burning man fellas. Any of you engineering minded folk out there would love it. Yes party, but also massive construction and fabrication projects etc. A lot of brilliant work and... welding.

Snuggles out.

 

All of the welds I have seen from Abe have looked very legit. Much better than mine.

To my knowledge, the only manifold of mine that has cracked was Sav's manifold. It tore the wastegate off, not along a weld but ripped the damn weld elbow material apart, in very short order measured in minutes. Unsupported longass wastegate tube = bad. Oops. He had it quickly patched at a track, failed again quickly, sent it all back to me where I redid the EWG tube so it blended back into the downpipe (and why I have never done a VTA EWG since) and ground out the cracks adn patched the thing together. Found a hairline crack near the flange along a weld, hence my square gussets on all the vband manifolds. I believe it's been fine since. No crane.

This is one reason why I do not recommend long tube/ramhorn manifolds.

 

So. Why do long tube / ramhorns work on other cars? Surely Full Race does not have to replace cracked-weld manifolds constantly. These tubes look pretty long.

 

Look at the size of the weld around the flange. Looks GIANT.

 

This.

Welders are like photographers. Every fool with a welding machine is a professional welder.

 

Come-on now, each application is different, even you know this.

Unrelated to application or weld quality, if you charge full-race price, you can eat a few manifolds now and then.

haha, quite true!

 

I was under the impression, years ago when they first came on to the scene and I was paying attention, that most or all of Full-Race's stuff was robot-tigged. Is that still the case?

 

Yeah, pretty sure it was one of the owner's senior projects to make that "robot" welder.

 

Far, I guarantee that manifold would have a support at the turbo flange. miata engines are known for their harmonics, harmonics will do strange things to parts. it probably doesn't help the manifold that you have all that weight hanging off of it. maybe a top mount would be a better solution.
.

 

Tim is absolutely right, now I don't know how much you paid for your stuff, but for a custom built header from a race shop or a header shop you would be looking at $1500-2500 for the header alone. I priced out turbo headers for my dart one time. 304 SS started at $1975, then I told them I wanted to do a single turbo setup and the price went up drastically to $3500 minus EWG dump tube, down pipe and exhaust. Since then I have just purchased a pair of flanges to build my own (on day I'll finish it). Now I'm not saying "you get what you pay for" but I personally own and have never had any problems with my ARTech stuff, the construction is gorgeous, the welds look great and the price was unbeatable. Now am I running 6,000 psi like you, no. But my car gets abused that's for sure. Not bashing on your build, personally I think it is badass and I have used many things from your build on my build, and saw what things to do and what not to do by your tribulations. I just think the matter should be held through PM's with Abe and not all over the thread with other people chiming in about their cracked manifolds and what not, because the fact of the matter is, we, nor you have any idea why it broke where it broke, just assumptions. Anyways, thats my .02. Abe is a great guy, I have dealt with him numerous times. And Tim, your **** is badass too, don't get me wrong! Keep it up with that KLDE swap, that thing is awesome. Keep up the build Fae, it's definitely badass

 

Today, I learned that even the "expensive" miata manifolds are dirt-cheap.

 

Not exactly true.

There is a reason FM use only a log style manifold. There is also a reason they sell a downpipe brace.

R&D

Going with a tube style manifold you have to assume you're going to run into problems like this. It's the price you pay for getting a little more HP. Brace that **** up!