So, I followed kboi's threads for a while since we have similar cars, and similar issues keeping our turbos attached. I did not want to go the route he did of drilling out my manifold and turbine housing and re-tapping them for m10 studs, then welding them on anyways so I ended up with a different solution. I am running Flyin Miatas inconel studs from their website. First all the things that did not work:

Stage 8 locking hardware - Not sure how, but it vanished, tried 3 separate times, put it on tighter every time.
Nord-Lock washers - lasted about 10 minutes and I blew my gasket
Welding nuts onto the housing (M8 studs and nuts) - Lasted almost a whole day before all the welds cracked and the nuts vanished.

The solution that has worked for me now, holding up to 3 hours of track time last weekend, is safety wire!

I purchased these nuts:
https://www.probolt-usa.com/titanium...-25mm-drilled/

Installed as pictured



I don't believe I have seen anyone else safety wire their turbo nuts before, not trying to claim I am the first, but since I didn't see anyone here try this yet, I figured I would contribute to the incredible knowledge that is on this forum!

If an admin sees this post by the way, I would love to have a complete offline mirror of this website, just in case one day it goes the way of Zilvia.net The information contained on this forums is priceless and irreplaceable. If there is a good way for me to mirror the site on a regular basis and keep a rolling backup of it, I would love to do that for you guys. I have almost 200TB of storage on my servers at home and cannot think of a better way to use some of that space than preserving the tome's of miata knowledge.

 

I've read @Midtenn 's build thread. I saw that he used safety wire on his setup. There was another post not too long ago that also used it.
https://www.miataturbo.net/build-thr...m_content=post

 

Very cool! Wish I was better at searching for solutions, would have saved me a dozen hours of frustration, probably that many gaskets, and $300 on solutions that didn't work!

I really feel like safety wire should be the automatic solution to nuts backing out. I feel stupid.

 

Thank you for the website though! I will be using Nord lock wedge washers for a bit.

 

By reading a zillion post on this site years ago, I finally solved losing/breaking studs on my Lemons race Volvo with T3/T4 turbo. It's not just nuts backing off, it is also studs stretching.

Did you resbond the studs to the manifold?

On my Volvo turbo Lemons car I did the following to the turbo to manifold over 20 races:
- Steel studs, stage 8 lock nuts - fail. Studs stretched and sheared
- Steel studs, squished nuts, nord lock - fail. Studs stretched and sheared
- Unknown studs that came with car (maybe inconel or stainless) with safety wire - lasted several races
- Full race Inconel 10mm stud kit (actually a286 steel I think) nordlocks, and resbond - never failed

On the turbo to wastegate:
- Steel studs, locking nuts - fail. Studs stretched and sheared
- Steel studs, locking nuts, safety wire - lasted a few races then fail. Studs stretched and sheared
- Stainless or Inconel studs, resbond, locking nuts - did not fail

McMaster 7604A56 is Resbond

 

My 2c: I had inconel studs with St8 locks, studs claimed to be Resbonded to manifold. No downpipe brace. Failed on drive across country, resulting in broken stud also. When dis-assembling noticed that the mani and turbo surfaces had chattered themselves out of flat. Started with fine file, then Dykem and 400 grit to get everything flat. Inconel 8mm studs w Resbond, safety wired nuts, downpipe brace. No probs since. I think flat surfaces and downpipe brace really help. Also, check the clearance of the Vee bands to the turbo outlet - my Vee bands required grinding to clear the EFR wastegate exit bump. I could not get stable idle AFR until that was done because the Vee band interfered with the bump and wouldn't allow the faces to seat.

Wombat

 

I have a turbo that bolts to the cast manifold. I weld 1/8" welding rod to the heads of the bolts in a rectangle pattern. The 5 bolt down pipe is bolted on then safety wired. These nuts are cool. Are there steel ones available?
I haven't lost any stage 8 nuts before. Not sure how you did. Maybe safety wire the clip to the nut.

 

A few thoughts and notes on my setup. After a year or competition, I tore everything down. I found that the nuts had loosened up some, but the safety wire kept them from coming off. Not sure if it was stud stretch or the safety wire stretching. There was a small leak between the turbo and manifold when cold (you can see carbon in videos below), but it would seal up once everything warmed up and expanded. I tightened up the nuts and switched to Inconel safety wire, but I only had one race weekend on setup before totaling the car and parting it out.

Having a down pipe brace greatly reduces the stress on turbo. Flex pipes do not reduce all the stress on the studs! See the videos below. The brace is something I fabricated from a f-body axle clamp and some plate I had.

Without downpipe brace:
https://drive.google.com/file/d/14ZU...ew?usp=sharing

With downpipe brace:
https://drive.google.com/file/d/1073...ew?usp=sharing