Turbo Coming Loose

[The Mafia]

Hey everyone, I have a simple question.

My Turbo to Manifold bolts keep coming loose. The Tabs that are there have finally broken from me bending them away to tighten the bolts etc.

Can anyone suggest something that I can use to keep them tight? Some kind of thread locker, or should I be looking at something else? Lock nuts are useless in this situation because the nylon will melt due to the heat.

Surely there is something out there that is heat resistant for this purpose?

I've also thought of other reasons:

1. Exhaust it putting too much weight and play on the turbo, working it loose

2. There is 2 x 10mm spacer plates and gaskets, could be causing a problem or helping it work loose?

3. Something wrong with the manifold bolts \ studs?

4. Maybe my atmospheric BOV is causing the turbo to fall off because its too fully sic uleh?

Hmmm.

Any creative input would be good.

Thanks

Jono

Edited February 26, 2008 by The Mafia

[RPMGTR]

You will need to use Inconel studs or they will keep stretching forever.....

cheers

[ZENNON]

Creative heh... maybe use some MARSHMALLOWS!!

[dano4127]

I would like to lock in 4 Eddy

[The Mafia]

You will need to use Inconel studs or they will keep stretching forever.....

cheers

thanks heaps, I didn't realise this.

Maybe I need to change the bolts too because I am not sure what we put in, and if they are stretching they might break...

[**RB2530**]

Yes get some good studs and nuts..Dont use bolts as you put more stress in the threads in the manifold when tightening them...Studs and nuts are high tensile so more resistant to tearing so you can get more tightening torque into them..

As far as thread locker on these I never use it....I use heaps of copper based anti seize...Never had one seize but never had one loosen...It lubricates the nuts so you cab get them tighter without damaging threads

Oh and never never never use brass nuts!! (I have been told to use them by Repco believe it or not). You may as well use plastic!!

[Guilt-Toy]

i use standard nissan studs and bolts and they never work themself loose

[**RB2530**]

Also make sure you tighten the nuts in a sequence. ie pull the flanges together with a light tension and then tighten each nut in about 2-3 stages...I go diagonally across the flange. Not sure what the Nissan workshop manual says about this but it would be similar...

[**RB2530**]

Make sure you atmo BOV is not facing the nuts...Maybe it is blowing them loose...

[GeeTR]

4. Maybe my atmospheric BOV is causing the turbo to fall off because its too fully sic uleh?

LoL, some wee came out

Get some stainless sheet, and make some new lock tabs - easy.

Your right i reckon, its prolly the spacer and wot not, increasing thermal expansion abnormally.

In cahoots with marshmallows, s.steel sheet is the jazzle frazzle.

Edited February 26, 2008 by GeeTR

[Wheezy]

Cone locks FTW

[discopotato03]

Mafia often what happens is people fit larger heavier turbochargers and remove the factory turbo's bracing .

I don't honestly have a clue where Nissan supported the std turbo on an RB25 but on FJ20's at least there was some interface I think between the bottom of their std cast dump and I think the gearboxes bell housing .

It needs to provide support in the vertical plane but allow backwards and forwards movement if the dump off the turbine housing is tubular - for lengthwise expansion and contraction .

A while back Sydneykid posted about the lengths GMS had to go to to support the race GTR's twin turbos .

Corky Bell also mentions that turbo exhaust manifolds lead a hard life and one thing they have to be good at is supporting the considerable weight of a turbocharger when they are red hot . Most manufacturers fit a brace and they don't fit anything they don't absolutely have to .

Also while I'm here I have heard stories about exhaust manifolds cracking on RB25's , it only seems to happen if the exhaust is not properly "hung" under the car and or it is too rigid . A big bore exhaust can put lots of leverage into a turbo and manifold , it can also ring like a bell and feed lots of resonant vibration into the cabin area and your brain .

Imo using the factory exhaust hangers or equivalent and maybe some sort of "soft joint" takes considerable leverage and drone potential out of drain pipe exhausts .

Cheers A .

Edited February 27, 2008 by discopotato03

[The Mafia]

Make sure you atmo BOV is not facing the nuts...Maybe it is blowing them loose...

This reply, simply cracked me up, 110%. Thanks for humoring me today..haha. f**k, we need more fully sic uleh liek this.

thanks for the great replies. I've got some thinking to do, and from what disco has said (thanks too) I will see if I can get a bracket made up to support the flange on my next manifold. Its probably going to be an extrusion honed job. And thats even more of a reason to brace it, as if it cracks I'm going to lose an expensive manifold.

maybe just a angle bar from the bottom of the head flange, welded to the turbo flange, either one or two. That way it will support the weight of the turbo.

As for the nuts commin loose, I've spoken to Dale_FZ1 and he said that the exhaust shops sell these special nuts that are meant for this kind of thing. So I'll grab some of them and whack them on. If they'd have to be the right material to withstand the heat if purpose built for exhausts.

Might be time to bolt on a extrusion honed manifold, and some new gaskets. I might even put the 0.82 rear on and aim for more power? Or maybe not, I'm happy with a V8 style 300rwkw.. haha.

700nm of torque at 3,000rpm feels great.

[Tangles]

pretty sure a FPR would work great !

Is there enough room on the studs for 2x thinner nuts? the outer nut can help hold it all in tight

The exhaust shop nuts is probably the go.

Or you could try hi-temp industrial sealant/glue to help hold the nuts onto the bolt.

[giant]

you must use , oem studs and nuts or Inconel (or other high tenstile studs) or you will have this problem for ever!

they will stretch everytime when the turbo gets hots and eventually break off and then you can have a drama removing them.

[dangerman4]

hey Jono

i used 4 stainless steel chem anchors with stainless nuts on my gt3582 with some never seize and no locking tabs.

and i run up towards 2 bar and they havent come loose at all so this might be a easy solution for you.

people saying use oem stuff. its impossible there too short

and the nut idea from dale in fine for the nuts but as said previously i think its your studs stretching not the nuts undoing.

the chem anchors i used were 12 x 100 style which is actually a 10mm threaded stud to suit a 12 mm hole + glue

they have a nice little 6mm hex on the end so you can screw them in and out with ease, all you need to do is cut them to suit your length.

[gotRICE?]

You will need to use Inconel studs or they will keep stretching forever.....

cheers

Not forever... just untill it stretches past the point of *SNAP*... doh.

[**RB2530**]

Try using these...

[**RB2530**]

Try using these...

[Adriano]

Have you considered upgrading them to M12 x 1.5's