I had the front 2 studs break last weekend, whilst at the track. I run about 10psi boost. This is the second time this has happened so my mechanic has said he needs to build a turbo brace, to support the turbo. He thinks it's the weight of the turbo snapping the studs.

Would firmer engine mounts help, by stopping the engine moving around so much? Just a thought before anyone shoots me down! I thought maybe the engine/turbo is moving as the engine revs, but the exhaust could be too rigid/fixed, putting extra strain on the bolts.

Is it an unusual problem or does it happen to most cars with a turbo system? If so, how do firms like FM sell their turbo systems without more comment/noise about this problem? Does it happen to everyone or is there something different about our set-ups?

 

Nope, we've tried that. Have also braced the downpipe to the transmission to try to limit any turbo/manifold movement, without success.

They sell their setup without addressing this issue because they don't drive their cars very hard, and the majority of their customers don't either.

 

You could weld 4 v-bands onto the head itself, but it would make manifold construction a bitch and it probably wouldn't be worth it. I've never had trouble with the head flange coming loose.

If I were sticking with flanges, what I would probably do is new studs with roll-pins pressed into place, and then nuts that have been drilled in a few places so they can be tightened when necessary. Drilling through the nut and stud means you can never tighten it - and you will have to tighten it.

 

V-Bands are the answer. Who wants my manifold, DP, and turbine housing?

 

Sorda on topic.... I dont plan on tracking it any time soon, but i was thinking of using these



They were stock on my SR20 and My turbo to mani nuts never once came loose. worth a shot?

 

Yeah worth a shot for sure IMO. That is easier than using the individual bend-up-tab type and safety wire. I have seen them sold somewhere before but cannot remember where. Anyone know where to get them for T2 flange spacing?

Hell I might try that and safety wired socket head cap screws on the DP flange. That is unless there is a similar product as above for a 5-bolt flange.

 

they are sold locally from my friend jeff at 240sxmotoring.com. They are for the T2 flange. Stock on all sr20det's. They do wear out. my first ones that were on the car originally did fail. put new ones on, never ever had an issue!

 

Excuse the ignorance - how does it work?

 

Does he make them for t25s?

 

The problem isn't the nuts or studs spinning though.... Safety wire solves that problem easy enough.

 

Have you ever seen the front sprocket on a motorcycle? Same kind of deal.

The plate goes under two of the four turbine inlet flange nuts. The fact that it is over two studs keeps the plate from spinning. Once the nuts are tightened, the two tabs protruding out next to the two holes are bent upwards against the flats on the nuts. That keeps the nuts from rotating.

 

Yeah sorry I should have said T25 according to the way Garrett identifies the turbine inlet flanges on the T25XX and T28XX series turbos.

 

I think if stainless studs and nuts were used to match my stainless exh mani flange, and the DP flange, then they should expand the same amount when they heat up since they will have the same TEC (thermal expansion coefficient - I am ASSuming that since they are is such close contact, their temperatures should be pretty close to the same). Therefore, they should not stretch, at least not to the point of yielding. If the nuts/bots/studs/whatever are kept from spinning, that should take care of it loosening. Or, am I missing something here?

 

How does that work exactly?
Spring pin - Wikipedia, the free encyclopedia
Is there an oval slot in the stud?

Mine has no room for that, I doubt the studs on the hot side can be made any longer:

 

what about this nuclear ****???
Extreme Temp Thread Locker, Turbo Rated - 034 MOTORSPORT

it says 2100*

I'd be a little worried about getting this **** out of the manifold if something bad happened.

 

just ordered the Resbond thread locker. I talked to the guy on the phone and he said they use it in racecars with cast iron, horizantally mounted turbos and its worked without failure.

 

Great, hope you found a gem there.
Using it on the nuts only and not on the stud end that goes in the manifold?

 

why not use it on both ends? The guy told me I could just "double-nut" the studs and they will come out. However, he said to only use one line accross the threads becuase using too much will make extraction seriously dramatic. It sounds to me like this **** is pretty hardcore.

Apparently they use it on several turbo VW racecars and he claimed that they've never had a failure with it. I should have my next track event in 3-weeks or so at Hallett. Fingers are crossed...now I just need someone in Little Rock to let me borrow a drill so I can extract the broken stud.

 

Good luck with that stuff Trey; I hope it works. I'll be waiting to hear the results. Hallett in June should be a good test.

BTW I found another threadlocker made by Aremco, Ceramabond 671, good to 3200F. Holy crap...
http://www.aremco.com/PDFs/Aremcocat2008FIN2.pdf
From matweb.com
http://www.matweb.com/search/datashe...63bbbbef74aad6

 

I ran across something while flipping through an old Summit catalog the other day. Not sure if they're available in the right size for us, but it's at least an interesting concept:

Available here and here.

Tech linky...

The story on these studs is that, once you've got the flange over the studs, you tighten the nuts...and then tighten a little set screw that's inside the stud end. This widens the diameter of the stud, making the nuts unable to loosen.
Given the issue at hand, I'd then have to wonder how secure the little set screws would be. However, it's another option to consider.