I did once but it hasn't been a re-occuring issue. like the turbo flange.

Bob

Has anyone tried something like an ARP2000 bolt or something even higher.. they have a pretty damn high tensile strength.

Aaaaaaarrrrrrrrrggggggggghhhhhhhhhhhh!!!!!!!!!

Not at 1700 degrees they don't

Dude, there is one safety wired bolt in a photo at the beginning of the thread. If you really need a red arrow pointing at it, I'm speechless.

You haven't grasped the cause of this issue yet. Try again.

https://www.miataturbo.net/attachmen...1&d=1298602955

That's supposed to read "MANI" as in MANIFOLD, and not "MAN". JPG over-compression...

So guys which bolts are we talking about again?
lmao

I have been making documentation, engineering notes and application notes for customers and for training engineers in-house for more than a decade. You don't expect your customer/audience to spend minutes figuring something out that a single arrow would clarify in seconds. YOU PUT THE ARROW IN THE DOCUMENTATION.

No I could not find the safety wire until you mentioned it. The original title did not say "CHRA". I looked at the pic and saw two humongous bolts with no safety wire. The Safety wire is BLURRY. The photo is over-jpeg-compressed. The two humongous bolts have no safety wire. So I ASKED. And did not get an answer.

Additionally, someone not familiar with the layout of his manifold and turbo would be thoroughly confused by his closeup.

For example, I did NOT know that Tial made turbine housings. When he said Tial, I thought, "wastegate". And, later, I thought "Vband housing" = "the fucking housing is attached to the CHRA by a VBAND. What's all this trouble regarding a fucking Vband bolt??"

I was not following Hustler's troubles carefully. I did not start reading this thread until it was several pages long. I do not want to read every post to try and understand what's going on. I wanted to understand WHICH GODDAM BOLT(S) are loosening. It was NOT CLEAR in his first post.

Let me repeat. When you show photos, you PUT ARROWS if it will prevent several minutes of confusion.

I'm not saying everyone here should do this, or there should be some mt.net rule about arrows. But it's NOT UNREASONABLE to ASK "WHICH FUCKING BOLT" and at least get an answer like "in the first photo there is an obscure bolt with safety wire that is BLURRY", like you answered, with sarcasm.

Hustler may have lost some opportunity for some readers to offer something helpful if he had put a fucking ARROW or had answered a not unreasonable question (another poster had expressed confusion, not just me).

</rant>

Sorry, I'm pissed because of work, and I'm pissed at the wife too.

:werd: I worked directly with PT's owner on a drag engine. Asked him twice for pricing because I wanted to sell his product. Nuttin. You'd think selling their products would be simplier. Tial is only marginally better too.

Got through about 4 inconel bolts tonight after work on one $3.50 drill. Niiiice.

Some random thoughts.

Maybe Hustler is overtorquing those small M6 bolts and thus pre-stretching them too much, making them more susceptible to creep due to high temperature.

Maybe the combination of CTE's of the materials is such that during thermal transients, they bolts ar expected to lengthen to a point that they creep or yield. In which case, extra spacers under the bolt heads will help.

Vibration - if his manifold positions the turbo farther away from the motor than cast manifolds, then the moment arm is longer, and it will probably vibrate more. Is it farther?

Additionally, vibration would perhaps make the bolts back out - but the safety wire prevent this - so maybe it's not vibration.

But again if indeed vibration is the issue, maybe the additional stress is making the bolts stretch by loading them past the elastic limit - again a higher temp rated bolt may help (but then he used some other high temp bolts), or maybe again, spacers will help, because any stretching due to vibration, occurs over a longer length of bolt.

If vibration were the issue, anyone who can rev the engine through the resonance frequency can break them. You don't need to be a he-man driver like hustler to do it, because hustler's he-mannisms produces high temperatures, not RPMs. IOW if the resonant frequency is say, 6000 RPM, then any pussyfoot who can make the motor sit at 6000 RPM for prolonged periods can shake them loose. High temperatures not necessary.

THEREFORE the problem is either HEAT, or the combo of HEAT AND VIBRATION.
Ergo the solution may involve something like a bolt that handles vibration better at high temperatures.

Which reminds me. Hustler rev the engine in neutral at slowly increasing RPMS. If there is a strong resonance it should show up.

Sounds logical to me and a great idea. Seriously.

Please take pictures and make simple diagrams with arrows pointing to things you describe but I don't know exist within your fancy threads about electrical gizmos so I can follow your threads without reading every post. :bigtu:

haha

Completely possible.

ehhh i'm drinking too much to post about this part or think if I'm correct but longer bolts would tend to be better generally like you mention below.

yes his CHRA is further from the engine than a BEGI or FM manifold.

Yes, and his higher temp bolts he tried were not safety wired and vibrated out quickly.

The difference is, my electrical gizmo posts are me sharing my information, while hustler is asking for help. I'm trying to help hustler and all I was asking was "which fucking bolt".

Sorry about the ninja edits, read the last 4 paragraphs I wrote above.

Intersting point! Perhaps the safety wire prevents backing out due to vibration, and the low temp bolts with safety wire cannot take the heat.

Sounds a lot like post #164 and what I think is the proper solution.

And don't all of our cars have a wicked harmonic about 5500rpm? obvious when you rev the car in neutral? I hope so or else I'm doing something very wrong.

5500 RPM may be the harmonic of the intake manifold. The exhaust mani/turbo combo may have a different frequency/RPM.

Maybe the solution is safety-wiring the non-inconel fancy hi temp bolts (Nimonic), which may be easier to drill than inconel.