Standard automotive studs. Steel I guess. Waiting for someone to come to market with something better....

Dunno. Felt fast. But Lotus club fails at timing. Iphone lap timer fails. I don't have a real lap timer. I fail.

Actually now I've taken time to read the Coast Fabrication link, I think SolarYellow510 might be right. The text describes them as locknuts so they may be the same nuts.
The triangular shape is very subtle. It's only really noticeable looking straight -on. They turn bone white after heat cycling. Moly coating perhaps?

 

Ask thesnowboarder how well Stage8 nuts worked.

 

Why not ask me? I USE THEM and so has 2/3'rds Cobra for the last 2+ years and 15+ track events. I only put about 5 track events on mine and while I may not be as fast as Sav or some of the other hot shoes, I flog the living crap out of my car. Neither one of us had any of these nuts loosen.

I didn't mean this was a solution to address the studs backing out/stretching, however if the intent is to prevent nuts from loosening then either safety wire or locking nuts work. There is NO way these nuts can back off. Stage8's or safety wire are the ONLY proven way to prevent the nuts from moving.

Addressing the studs movement is the priority of this thread, however when you guys are talking about nuts backing off then my statement stands.

Also, since they are not stover style nuts they won't deform or hose up the studs, which is another plus, yes?

For the record, my best lap last year @ laguna in my pig heavy 1.6 turbo running ~180rwhp on hoosiers was a 1:47xx and then in the afternoon I switched back to my full tread RA1's and my best lap was a 1:49xx. Not great, but not bad either. On par with typical SM lap times there. I was still fighting cooling issues so I could only get 2 hot laps in before I had to back off, then in mid afternoon one of the oil pump bolts backed out and dropped into the timing belt and tore it to shreds. Perhaps I should have put stage-8 bolts on the oil pump, LOL. I blew the engine at the next event @ Bwillow :( and haven't hit the track since, except in a rented SM earlier this year.

 

Stage 8s hold the nut on - doesn't mean a damn thing when the stud expands, then backs out THROUGH the nut, falls off and take the nut/lobe/clip with it. Nick (thesnowboarder) lost one.

I won't be using safety wire for my test in 2 weeks - although I may try a variety of different nuts to see which ones hold up the best. ATP copper locker on one stud, 034 aircraft grade on another, standard metal locker on one, and maybe a Stage 8 on one.

 

Yup, agreed. I wasn't commenting on the stud issue, just the nut back off issue.

It's too bad we can't fit stage8 bolts for the turbo to manifold connection.

 

Wouldn't solve the problem anyway.

 

I had fun running around with you at Laguna earlier this year



As you can see in the picture, the upper stud was on its way out too. It did keep the nuts from backing off, however the stud decided to spin through the nut. My next step would have been to res bond it all together.

Sav, i think that it's a good idea to try different nuts. Keep in mind, as i am sure you know, that the most front ones seems to take the most stress.

 

Aside:
Hey all you materials/shopping/smart people, check this:
https://www.miataturbo.net/forum/t39274/

 

Any updates on either of the 3 stud solutions? I have my manifold off the car currently to resurface my warped turbine side flange. It would be nice to put something permanent on when I bolt everything back together next week with my upgraded compressor wheel....

 

Get 304 and Resbond or tack weld*. Keeping up for >3 events so far and driving way faster than before when it all fell apart.

*) Tack weld is what I have, Resbond would do the job too I presume. Those were actually *used* 304 studs that came loose before. Resbond on MF thread, flange nuts, tighten like hell, tack weld, done.

 

I'd like to order them now on mcmaster while im at work so they might ship out today. I can't for the life of me think how long I need to get them. 30-35mm long enough? Also, all they have in SS is fully threaded rod studs. Will that be a big issue?

 

38-40mm long. My begi ones were 38, and my McMaster ones were 40.

 

My solution is just too expensive and the competing product would completely demolish any chance to redeem the money. The material was A286 1800/1325F* heat treat. Its far superior to any other fastener material in this application. You won't find it anywhere for less then a 100 dollars for 4 studs. More likely in excess of 40-50 dollars a stud.

 

I have 8 Inconel prototypes on the way. I was hoping to have them for this weekend, but their estimated ship date is at the end of September now. I am hoping to have them in a test car for a track day at Thunderhill on the 2nd and Buttonwillow on the 3rd.

 

Our material just arrived yesterday. It is with the machinist right now. I expect we will have studs going out to people to test next week.
Stephanie

 

I run ~40mm full thread rod of 304.

 

Stephanie,
If y'all need someone to test yours out on a Greddy, I'm Local and might have atleast two more trackdays before the end of the year.

Chris

 

Was a poll ever taken on if this was happening soley on begi/fm cast manifolds or not? Sorry to repost if it was.

Recently, about a month ago, I had accidentally locked my ign at 15deg and was seeing egts hot enough to nuke a turbo blanket rated to 1800F continuous. It warped the turbine flange on my manifold (1/2" thick), and I could visually see the manifold and downpipe glowing bright red. That has since been fixed.

Yesterday I pulled my manifold to resurface the flange and after reading this thread I was surprised to see that all my nuts were still nice and tight. Even more surprising was that I actually needed to use vise grips and enough elbow grease to break a crank bolt loose in order to remove the studs. Now I'm not running on the track yet, but the temps my manifold was seeing are likely in excess of what you guys see on the track, and for just as long of the time. Yet I did not experience the same issue of studs spinning out. The studs in the manifold were just grade 8 M10x1.5. Granted the tap ETD used makes the studs a tight fit (a good thing if you ask me). Also, my external wastegate is above the turbo and it is likely that its connection to the downpipe is acting as sort of a brace.

I replaced everything with stainless 304 that I sourced from a local True Value store. The new studs were still a tight fit putting them in and I used resbond on them as well. Granted I will not be going on the track to give them a beating, and I'm not going to be locking my timing at 15deg to test them again either (I'm like hustler, I don't plan on taking this **** apart again if I can avoid it).

It seems to me from reading that this issue seems to be limited to people using a cast manifold, and/or a manifold that positions the turbo in a side mount configuration placing the majority of the load on the top 2 bolts.

Take it how you will, if you want to dismiss my experience because I don't run sub spec miata lap time I'm fine with that too. Just thought I would share my experience.

 

i recently had to replace my greddy bolts that had been seeing 15psi for years with no issues. i turned the boost up to 20 psi and at took about half an hour to stretch the bolts enough that the turbo could move about an 1/8th of an inch in each direction. i've moved to studs and locking nuts i had sitting around from an eclipe i had forever ago. been running 18psi no issues yet

 

The studs don't spin out, they are plastically deforming.