Jump to content
SAU Community

Recommended Posts

hi all,

i know that when a stock turbo fails on the gtr, the ceramic dust gets sucked into the engine and kills the engine. However i have only heard of this happening to r32's and r33's , mostly r32's. Has anyone heard of this happening to r34's . I know for sure that all r32, r33 and r34's (except the n1 and nurs )

have ceramic wheels so the potential is their. But i still haven't heard of any r34's doing this. Does anyone know of any r34 gtr's who have had their engine killed by the ceramic dust.

regards

mike

Link to comment
https://www.sau.com.au/forums/topic/221039-turbo-failure-on-rb26/
Share on other sites

Ceramic dust??? How does dust from the exhaust turbine get into your engine?

I was under the impression that when the turbo's fail it's the ceramic exhust wheel that delaminates from the shaft due to the glue/bonding agent can't cope with the additional heat generated by extra boost. If you continue to run the engine after the exhust wheel has delaminated then the whole rotating assembly will be horribly out of balance, causing the metal compressor wheel to scrape the compressor housing and sending fine shavings of metal through your engine.

Ceramic dust??? How does dust from the exhaust turbine get into your engine?

I was under the impression that when the turbo's fail it's the ceramic exhust wheel that delaminates from the shaft due to the glue/bonding agent can't cope with the additional heat generated by extra boost. If you continue to run the engine after the exhust wheel has delaminated then the whole rotating assembly will be horribly out of balance, causing the metal compressor wheel to scrape the compressor housing and sending fine shavings of metal through your engine.

The shafts in turbo chargers spin at speeds in excess of 100,000rpm. So there is no point hypothesizing about where the bits of turbine wheel, shaft & housing are going to end up because the answer is everwhere. Including in your precious RB26.

I wouldnt be worried about turbo pieces going in your engine mate, most turbos fail at the exhaust side of the scope, I had a twin turbo engine previously and blew 6 turbos on it, never had any drams with engines, you see when one turbo fails the other turbo can not produce enough boost to even read 3 psi (read from gauge) , because pressure will always take the easiest option out, meaning that one turbo has failed and the other will just basically push air in to the other one because its closer (pressure follows path of least resistance) so i would imagine that as soon as the turbo fails there wouldnt be enough pressure to even push it through your FMIC etc . . correct me if im wrong just a thought!

you know, that is the reasonable answer.

But I have seen so many GTR engines killed by ceramic turbine failure (including my first, virgin rebuild) that it is just not true. when the gtr turbs let go you can end up with material in the bore that stuff it, badly. no difference in the 32-34 except for its age

I wouldnt be worried about turbo pieces going in your engine mate, most turbos fail at the exhaust side of the scope, I had a twin turbo engine previously and blew 6 turbos on it, never had any drams with engines, you see when one turbo fails the other turbo can not produce enough boost to even read 3 psi (read from gauge) , because pressure will always take the easiest option out, meaning that one turbo has failed and the other will just basically push air in to the other one because its closer (pressure follows path of least resistance) so i would imagine that as soon as the turbo fails there wouldnt be enough pressure to even push it through your FMIC etc . . correct me if im wrong just a thought!

Use the search button and you will find plenty on this topic . I even posted pics a few years ago for the none believers to see what happens to the engine . It is the exhaust wheel that lets go and becomes dust, gets sucked in via open exhaust valves and the rest is history....

My theory is that it is due to cam shaft overlap. The exhaust valves don't shut completely before the induction cycle starts. There is therefore some return of exhaust gasses from the manifold which now contains the ceramic particles that used to be your exhaust terbine.

  • 7 months later...

Thought I'd bump this thread since I couldn't find anything rb25 specific, and I suppose my question doesn't differ much anyway. Short story is my turbo went, compression came back as 125psi on each cylinder, dry test (r32 rb25de-t) Now I'm in the process of getting the new turbo put in and uprated injectors. Turbo was a slide hi flow

Now the compressor wheel did lunch itself, the mechanic found light metal shavings behind the pod, and some small bits near the IM. Now since my compression test came back ok, is there anything else to watch out for, or is it probable that the engine is ok if the compression tests consistent? Only idled the car once or twice after the turbo went, and tried to boost it twice 30 secs or so after the turbo went. Pretty much figured the turbo was stuffed when it didn't boost.

Getting the FMIC and all the intercooler piping flushed out as a matter of course. Also new engine oil and filter, since the turbo was leaking oil when I shut it off.

This is a known fact.

ceramic particles traveling that fast aren't going to be stopped by exhaust gas.

Imagine shooting an bullet (even if very small) into your exhaust port against the gas flow.

Slaughter and others;

* the damage occurs through the exhaust port . Not the intake.

Compressor side failures while being bad arent as bad as an exhaust side failure on a GTR. A compressor side failure still blows its air through your intercooler which does filter it a little. Compressor side failures will probably never happen on a gtr with stock turbo's anyway unless the intake injests foreign particles that cause the compressor wheel to break.

Like Rev210 says with his bullet theory. Consider the inertia energy of a wheel spinning at 100,000 rpm. Its going to go wherever it wants to go when it comes off the shaft. No amount of gas flow is going to changed the direction the wheel wants to go.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...