JasonC SBB

SS studs may need graphite or moly lube and thus may be incompatible with Resbond.

Savington

iTrader: (31)

We appreciate it, but we're just saying that your "fix" isn't a fix unless you have multiple hard track sessions under your belt with no failures.

BTW - I've made safety wire fail.

AbeFM

iTrader: (3)

You might have trouble getting studs much bigger than that on there - as I said, I had to grind the housing just to get the nuts on.

Good locking nuts are likely more important than locking washers. There's always the bent-tab style (along with wires), the idea being to keep things from spinning. Then even if they stretch, the worst you have is a bit of a leak. But it's a lot harder to stretch the bigger studs.

SolarYellow510

I'm lodging my support for this theory. Factory turbo cars don't have this problem. I've never heard of an S13/14/15 Nissan with the problem. All the pics in this thread show no turbine inlet gasket. Seems like that's what everyone does because Keith told them to a long time ago.

All it takes is the cast iron expanding beyond the yield point of the bolt, and it reduces the clamping preload. That's why you have to chase the torque multiple times. The stud is continually stretching. Someone should accurately measure the length of each stud to a thou or half a thou before installing it, then take it out and measure after chasing the torque a couple times. Bet it stretched.

SolarYellow510

Also, if you're changing to M10, make it M10x1.25 so you can use Toyota studs. They are really nice. And the nuts look good, too.

That sounds queer.

orion4096

iTrader: (22)

I have a new Begi-S kit going in sometime soon. Should I resbond the studs and nuts for the first install or heat cycle it a few times without the resbond and then put it on?

Faeflora

iTrader: (2)

How do OEMs keep their studs and/or nuts from falling off?

There's millions of factory turbo'd vehicles that aren't experiencing BS like this.

I think you guys are trying to hard. Is there any way we can get data on OEM R&D department proven solutions?

Skittles

OEM turbo manifold are usually longer and the junction between the manifold and turbo is firther away from the head and does not heat like a **** as in a miata. Talons, SRT4, and others have a little more runner length. Most aftermarket kits for Hondas have more runner length too.

Even the Mazdaspeed has the turbo a little further away while there are so many good reasons we think it should be on top like Begi and FM does...

Just trying to think differently.

kenzo42

iTrader: (6)

Oem turbos loosen when tracked too. The keyword i
s tracked

Faeflora

iTrader: (2)

OK well then um how about any turbo engines from pro teams? Maybe someone might have some connections on a GRM forum.

AbeFM

iTrader: (3)

Yeah, OEM stuff isn't much tracked. :-)

That's a general issue in the miata world. Makes sense since he's right more often than most. But taking anyone's word as gospel is ridiculous.

Here's the thing: Don't stretch the bolt beyond it's yield point. Why do you think larger studs help? Because to hold on what you need to hold on, just put a small torque on the bolt and leave it. That's the answer to the heat cycling. :-)


Part of the reason to keep them short is to keep the heat in - if you made them longer, you'd still want to do what you can to keep the heat in, and then you'd have your same issues back. Why waste the energy leaking heat out?

Then again, you get much more from good flow than not. Long manis tend to crack often, so really, cast is better anyway. :-)

hustler

iTrader: (6)

I discovered inconel turbo gaskets today. Too bad they're only in Supra sizes:
Twins Turbo Motorsports, Inc. - Inconell T-6 Turbo Gasket

Yes, the turbine housing has an inconel heat shield around it too.

y8s

iTrader: (8)

what's so great about inconel gaskets? are they better than zero gaskets?

railz

iTrader: (33)

I was looking at the wide selection of "locking nuts" on mcmasters website
would anyone recommend any of these?

McMaster-Carr

Laur3ns

The OEM exhaust nuts are M10x1.25 distorted thread with flange.

Nut Type Locknuts
Locknut Type Distorted-Thread
Distorted-Thread Style Oval Lock with Flange


I'd choose them in M10x1.5 for the turbo.

hustler

iTrader: (6)

The wing-nuts should work best.

y8s

iTrader: (8)

seriously, just turn them each lap to tighten.

...

if you're going to use regular nuts, go to an audi dealership and ask for them.

Laur3ns

Another update: turbo is now off the car. Studs look fine, nuts spin freely and studs came out easily. What a difference from the steel studs I had before, DAMN. They would just not move and break off.

You can see stud #3 has the threads flat from where the turbo hung when the nut flew off.

Before, they wouldn't come out and nuts would hardly move. Going to do new studs, and Resbond the hell out of every thread.

I've now got the car to a point where I can remove the turbo without removing or even loosen the manifold. Yay!

Laur3ns

Those are M10x1.25, like the Mazda ones. Unless you got an Audi p/n for M10x1.5

Project84

iTrader: (2)

My friend's Supra turbo uses gaskets between the turbine flange and the manifold flange... OEM. He beats the **** out of it and hit the dyno the other day, never has any problem w/ loosening nuts/studs. Granted, no trackdays yet, but as far as I know other turbo supras don't run into this problem either.

What if the OEM gaskets (copper?) are there to absorb the heat and expand, and since you guys aren't running them/any, the next quickest means of heat absorption is the studs/nuts.