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Old 12-05-2011, 03:22 PM   #21
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Wow thanks for the info, I had no idea. I got my Tial housing less than 2 months ago - how would I know if the bolts are the newer inconel variety? Is Inconel magnetic?

I should be able to drill the bolts myself, I do have a mill available and some cobalt drill bits.
If you got the Tial housing less then 2 months ago it should have the Inconel bolts already. You could give them a call just to make sure.

As for drilling them yourself, goodluck. I know hustler has a shop that does Electrical discharge machining that was able to drill the bolts. TurboTim works at Jesel Valvetrains and they had a machine that can do it. I know Savington does not have any local machine shops that he trusts to do it.
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Old 12-05-2011, 04:00 PM   #22
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FM's brace is a good example of this: http://www.flyinmiata.com/index.php?...umber=06-97577
Why not move it further back like I did, "behind" the flex joint. Do you want 9' of pipe behind the hard mount, or 2' like mine?

Check with Tim first, but if he can't do it I suggest you go the EDM route. Don't waste your time taking these to any-old machinist, most guys don't get it. The EDM drilling took a whipping 15 minutes for 6 bolts...not bad for $100 in labor, lol.
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Old 12-05-2011, 04:31 PM   #23
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I built this on the same principle of the FM one. Over-engineered to my liking.

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Old 12-05-2011, 04:57 PM   #24
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This was discussed in this thread (about FM's exhaust brace):
https://www.miataturbo.net/flyin-miata-miata-accessories-48/fm-exhaust-brace-43572/

In it bbundy talks about and post's pictures of his failed U-bolt clamp's. He suggest's using a 1" metal strap in conjunction with a flex pipe instead, as it has worked for him for quite some time.
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Old 12-05-2011, 07:43 PM   #25
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Originally Posted by hustler View Post
Why not move it further back like I did, "behind" the flex joint. Do you want 9' of pipe behind the hard mount, or 2' like mine?

Check with Tim first, but if he can't do it I suggest you go the EDM route. Don't waste your time taking these to any-old machinist, most guys don't get it. The EDM drilling took a whipping 15 minutes for 6 bolts...not bad for $100 in labor, lol.
I am considering all three actually.

1. Manifold "crane" if I can get it to fit, or a BEGi manifold brace. I will likely have to weld some mounting tabs to the manifold for this. Even if I made a bracket to bolt to the turbine housing I would run into the problem of the turbine housing bolts being too short, and since they are inconel I don't want to try to find longer ones!

2. Exhaust brace in front of the flex joint, bolted to the tranny. This would be a custom piece, not a muffler clamp per bbundy's advice.

3. Some additional exhaust hangers mounted horizontally, aft of the rear end to restrict side to side movement without adding NVH. I am dreaming of something like the Cannon subframe brace but with exhaust hanger mounts incorporated.

Hell, I have all winter to get this thing done. And anything worth doing is worth overdoing
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Old 12-05-2011, 09:11 PM   #26
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I'd suggest a turbo-to-block brace over a crane-style one. Four cyls are thrashy and you want to raise the natural frequency of the turbo/manifold system. That's what a brace can do that a crane cannot. For OEM examples see MSM, Evo 8-9.
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Old 12-05-2011, 09:24 PM   #27
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Originally Posted by JKav View Post
I'd suggest a turbo-to-block brace over a crane-style one. Four cyls are thrashy and you want to raise the natural frequency of the turbo/manifold system. That's what a brace can do that a crane cannot. For OEM examples see MSM, Evo 8-9.
Thanks for the advice. Just so you know, ever since I saw your custom bottom mount 321 manifold on the blue car I wanted to copy it.

Anybody got a picture of the Mazdaspeed brace handy? I searched but no luck yet.
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Old 12-05-2011, 09:51 PM   #28
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Quote:
Originally Posted by JKav View Post
I'd suggest a turbo-to-block brace over a crane-style one. Four cyls are thrashy and you want to raise the natural frequency of the turbo/manifold system. That's what a brace can do that a crane cannot. For OEM examples see MSM, Evo 8-9.
I thought about this for a long time on my AF parts and I have no idea how to do it and make it work. Like any other red-blooded American, I gave up and went to the track,
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Old 12-06-2011, 01:12 AM   #29
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Quote:
Originally Posted by JKav View Post
I'd suggest a turbo-to-block brace over a crane-style one. Four cyls are thrashy and you want to raise the natural frequency of the turbo/manifold system. That's what a brace can do that a crane cannot. For OEM examples see MSM, Evo 8-9.
Id much rather put a compression load on a cast iron block than a tensile load on relatively thin cast aluminum cylinder head. I kind of cringe everytime I see an aftermarket engine damper attached to a cylinder head, I cant believe those things dont cause damage more often.
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Old 12-06-2011, 01:20 AM   #30
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Anyone know where I can get a wastegate tube flex joint like the one in this picture? The one I bought from TRE is too big and I can't fit it up near the WG like it should be.
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Old 12-06-2011, 03:55 AM   #31
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Originally Posted by mx592 View Post
Anyone know where I can get a wastegate tube flex joint like the one in this picture? The one I bought from TRE is too big and I can't fit it up near the WG like it should be.
From Vibrant: http://vibrantperformance.com/catalo...1022_1064_1254
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Old 12-06-2011, 12:51 PM   #32
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These are two pictures of how my waste gate tube plumbs back into my downpipe. I also want to say that my crane is more for the weight of the manifold and turbo, then for bracing the down pipe.

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Old 12-06-2011, 03:00 PM   #33
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Thanks, I just ordered one. Anyone need a braided 1.5" flex joint from TRE? I have a spare!
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Old 12-06-2011, 03:04 PM   #34
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These are two pictures of how my waste gate tube plumbs back into my downpipe. I also want to say that my crane is more for the weight of the manifold and turbo, then for bracing the down pipe.
Thanks for the pics. Is that a double slip joint or a single? I ordered a single but now I am kinda wishing I had gotten a double. I have this fear in my brain that putting the O2 sensor after the slip joint is a no-no, since any leakage could introduce fresh air and throw off the readings. This would be reduced with a double slip, I imagine. Am I just being paranoid?
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Old 12-06-2011, 03:08 PM   #35
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Thanks for the pics. Is that a double slip joint or a single? I ordered a single but now I am kinda wishing I had gotten a double. I have this fear in my brain that putting the O2 sensor after the slip joint is a no-no, since any leakage could introduce fresh air and throw off the readings. This would be reduced with a double slip, I imagine. Am I just being paranoid?
It is a double slip joint. I have not ever worried about fresh air leaking in. Neither has hustler, or savington, or any of the other people who have bought Absurdflow setups.
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Old 12-06-2011, 03:08 PM   #36
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I still don't understand the advantage of bracing the DP at the trans and leaving 10' of heavy pipe behind it over my example. Engineers, enlighten me.
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Old 12-06-2011, 03:50 PM   #37
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Originally Posted by hustler View Post
I still don't understand the advantage of bracing the DP at the trans and leaving 10' of heavy pipe behind it over my example. Engineers, enlighten me.
From what i've learned in Statics it still doesn't make much sense, from an engineering perspective anyway. My only guess is that as long as you're isolating the movement from your turbo manifold/turbo to downpipe studs the rest of it doesn't matter so long as you've got a flex in there after the brace.

Your method seems to make sense, but I'm not so sure it would isolate the turbo hardware well enough. There is still going to be a lot of flex happening between that rear brace and your turbo manifold in the exhaust/downpipe. Perhaps both methods combined?
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Old 12-06-2011, 05:17 PM   #38
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I still don't understand the advantage of bracing the DP at the trans and leaving 10' of heavy pipe behind it over my example. Engineers, enlighten me.
It only really works if there is a flex joint after the brace. The exhaust movement is not harmful (just annoying if it moves far enough to hit something), so long as there is a flex joint present to eliminate or at least greatly reduce the moment that the exhaust would otherwise put into the downpipe/turbo. Without the flex joint, the brace just acts like a fulcrum. It will alter the loads experienced by the turbo (more side load, less torque) but it won't be as effective as it would be if there were a flex joint just aft of it.
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Old 12-06-2011, 05:19 PM   #39
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Ok. I mainly did this because my diff housing was beating a hole into the pipe, then I realized that it propably helps the turbo out a bit.
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Old 12-06-2011, 06:11 PM   #40
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My current system that has worked for a number of years now. Diving board support off the motor mount to the turbine outlet. This is very similar to what Mazda does on every B6/BP OEM factory install.
1” wide band clamp holding the downpipe to the transmission.

The two failures I have had.

1) Bell housing bolts holding the transmission bracket came out. Forgot to tighten them after a transmission swap. One track session later and the nuts holding the downpipe flange to the turbine outlet were loose and two of
the studs broke off.
2) The single bolt connecting the diving board to the to the turbine outlet flange broke off once. A few sessions later and the manifold became cracked near the turbo flange. Also the first diving board I made out of mild steel and it cracked. current one is made of 4130 plate and hasn't cracked.

I have since added a 1” long spacer to the single bolt on the diving board. It gives the bolt a longer length and ability to stretch some without yielding and it hasn’t snapped since. Using 10mm Inconel studs with Nord locks seems to have almost cured the turbine flange to header problems as long as my two other supports on the downpipe stay functional.

My prior experience with Using U-bolts around the downpipe to secure it were not good. A U-bolt doesn’t have enough bearing surface on the pipe and you can’t keep it securely tight without it crushing the tube after some heat cycles it loosens up as it crushes the pipe.





Bob
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