Stud Creep
 

I'm having an issue with a couple of my manifold studs coming loose every so slowly while I'm at the track.

My hardware:
Mild steel log manifold
T3 turbo
Track speed stud kit

My flanges are flat, resbond used, and the retainers are snug against the turbine housing. I'm good for a couple hours on track, but over time the nuts become loose because the studs have turned.

What options do I have to keep the studs secure? I'd weld them in place, but holes in the manifold flange are closed on the back side. Would welding the nut the stud prevent the stud from creeping since the nut is secured by the retainer?

yikes, looks like you're using the right stuff, and still backing out.

maybe this?
https://www.miataturbo.net/attachmen...ine=1410147419

try re-applying the respond? If you have already then that's whack. Speak with trackspeed. the expensive easy way is to go v-band.

I have the stage8 fasteners. Came with the kit. They are doing there job.

I have my own bottle. I applied liberally and allowed it to dry for two days before installing the turbo.

Yeah, vband would be nice, but I need to work with what I have.

Not sure this would weld anyway due to all the dissimilar materials.

I'd be shocked if your studs are actually turning. Did you mark them somehow? How do you know they're turning? You could take a reference photo of the "TSE."

I'm kind of suspicious of your manifold. Mild-steel? That's not the proper material for this job. You need cast iron or a high-temperature stainless. My guess is that the threads in the mild steel flange are creeping enough to loosen the assembly.

since when is mild steel not proper material?

both tim and abe use the stuff on most of their manifolds

From what I've seen, they mostly fab in stainless. ?? I don't think I've ever seen a mild steel turbo manifold. Maybe we need pics of op's manifold.

Mild steel that is subject to fastening forces (ie, threads) will let go at elevated temps. It's a physical property. It's why we use inconel studs. The turbo mounting flange threads see basically the same temps and forces.

Which two studs are coming loose?

The top two came loose. 2hrs track time on Sat, no issue. But when I started pushing things a little harder yesterday, I was able to turn the nuts maybe 50 degrees.

I did not mark the studs, but it seems to be the only logical solution since the nut cannot physically turn due to the stage 8 fasteners.

The manifold was fabricated by Abe at ARTech this year. My understanding is that he no longer builds manifolds out of stainless because they crack.

For this to be happening the stud would need to be turning in both the nut and the manifold at the same time. Which wouldnt work. I dont know where TSE sources their studs but we've had indian and asian sub-contractors blatantly forge material certs before. The studs stretching makes a lot more sense in this situation since you have the stage 8 nuts. I'd want to mic the length of all 4 studs and note their lengths then re-install and wait for this to happen again, then re-mic and compare. In the threads in the manifold were creeping they would probably be completely destroyed at this point.

US supplier, certs in hand. I've had several customers neglect to use the Resbond provided in the kits who have seen the studs wind completely loose and take the nut/locking hardware with it. That's why we include the Resbond. You have no idea what you are talking about, as usual, and I would appreciate it if you would take your grossly uninformed and potentially libelous commentary elsewhere (or better yet, keep it to yourself entirely).

Threads in the top two holes in good shape (no wiggling of the studs? Studs were bottomed out on the shank when they were installed?

Could you explain how the sud can unwind and take the locking hardware with it? If the stage 8 fastener works properly the nut wont be able to go along with the stud, unless one or the other is reverse threaded.

RE: Libel. I was taking all the blame off you bother and putting it on your supplier or supplier's supplier. IE, it wouldnt be your fault if someone 2 stops up the supply chain made a bad decision in the name of trying to save a buck. I've had material certs in hand from the sub contractor that said tested to rockwell 45c only to bust a gut laughing when the machine spat back at me 15c. This stuff happens, but if you're American all the was its incredibly unlikely.

If the stud unscrews so far that it no longer has threads engaged in the manifold, then the stud will fall out, taking the nut and locking hardware with it.

I've been through this horror. I had a BEGI cast manifold that had seen so many abuse that the threads just didn't hold anything longer than a few laps.

The TSE kit is the best you can get, but you need an almost brand new manifold to make it work. In that respect the TSE kit is not a last resort after everything else fails, because by that time your manifold threads are shot.

I'm now all V-band and it's heaven.

The manifold is new, so the threads are good as far as I can tell. There may be a tiny amount of wiggle in them, but less than the stud/nut relationship.

The studs are bottomed out in the manifold, but not to the shank. In order to get them to the shank, I'd need to shorten the stud. Once bottomed out, there is no wiggle whatsoever.

I just checked the nuts, and they appear to have stayed in place for an additional hour of track time after I snugged them down. And this was without the aid of the retainers.

Part of the issue is likely the stud being too long (not specifically designed for your mani), which doesn't let you preload it into the manifold. Resbond bandaids it into working anyway but the top studs are also supporting the weight of the turbo with your manifold, so they fail first. I've never tried to shorten one of the studs, but it's probably doable with an angle grinder and some patience (hacksaw need not apply). Don't cut too much off, you want as much thread engagement as possible (if for no other reason than to give the Resbond something to grab).

Any thoughts on welding the top of the stud to the nut?

Thanks for the support. Appreciated.

I wouldn't do it. I doubt the Inconel would play nice with the stainless turbo nuts. Cut the studs down, re-Resbond, and try it again.