How do I stop this? Any special tricks? I tried locktight, but even that only lasted a couple weeks. Its the bolts between the turbo and the manifold to be exact

 

try these

 

You could also try re-torquing once they have heated up

 

wouldnt that risk just stretching the studs or potentially breaking them?

 

Possibly, But maybe they aren't being torqued high enough in the first place?

Sometimes, when I have seen exhaust manifolds loosen bolts, they easy fix is to warm them up and 'snug' them up. (usually its only 1/8 of a turn or so)

I don't usually break stuff, well there was this one time....(6mm thread and 1/2" double impact)

 

everything I read and been told you are to re-torque exhaust bolt after they warm up before the cool down. On the Talon after swapping the turbo, I had to left the turbo warm up and then re-torque the turbo bolts and one had room to go.

 

good tip!

 

These things are great....They held my rear tire in place on my fixed gear bike, nothing else would work.

 

Can you get them anywhere else besides FM and in different sizes? I need 3/8"

 

just search for Serrated Flange Nuts or Serrated Washers

 

Yeah, this am while I was sobbering up.. I remembered the days before torque-to-yield bolts and everything including headgaskets need to be re-torqued after 500 miles. Almost every cast iron manifold need to be re-torqued when warmed up as well.

 

You can get them directly from NORD-LOCK.Just google it.

 

Home depot?
Fastenal?

Or we can always special order them,
Stephanie

 

About to buy hardware for my build and remebered there are issues with this.

Anyway, these puppies are also available from mcmaster-carr, 10 bucks for a pack of 5 pairs in 5/16.


Real reason I'm bumping this thread, I hear that its good to use stainless hardware. As an engineer/scientific type I started checking material properties and it look like steel is stronger AND has a lower CTE, but I know the nickel content in stainless will help it retain strength in high heat.

So, what has been the empirical data from you guys on this? Plain steel re-torqued when heated or stainless re-torqued when heated? I know all you super serious guys go for v-band setups and inconel housing bolts, its too expensive for my wallet and unnecessary for my skill level at the moment.

 

You buy the TSE Inco bolt kit. Yes, it's a lot of money; no, you never have to touch them again.

 

You and others on the board have done GREAT work on this issue, I'm not trying to dog that. The thread on your CHRA bolts (https://www.miataturbo.net/general-miata-chat-9/chra-turbine-bolts-relaxing-55717/) is fantastic.

Inconel just isnt in the budget right now, and I dont really track this car, just autox and mountain carving once a year. I dont think I'm serious enough for inco yet.
-Brad

 

I got a bag of 12pr on ebay for $6 shipped. I tried everywhere locally, both national and independent retailers, and could not come up with any without spending >$1 per pair which I thought was a joke. And nobody had them in stock...all special order.

 

For anyone in the San Diego area, you can grab the nordlocks at Marshall's Hardware on Miramar Rd.

 

All I can say is that I have FMs newer manifold (the older design allows the studs come intodirect contact with exhaust gasses...new one does not) and had them tap it out and install 10mm studs. With several track days and about 2 seasons of autoX on them, they have never flinched. With the older stuff on 8mm studs even street driving caused stub problems. Come to think of it, I should ask FM what studs they installed i nthe manifold.

 

I think the Stainless Steel 308(??) type studs are a sol'n that's halfway effective between ordinary studs and the $$ Inconel studs.
They're the same material used on boilers - there's an ASME standard alloy for them, and yes they have better high temp creep and CTE characteristics than the ordinary studs.