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With valve overlap and timing you can still get bits of ceramic into the combustion chamber. Exhaust gasses aren't continuously flowing out of the engine and in that short time when they are not you will get a neg pressure, backflow depending on manifolds, exhaust system, valve overlap etc. So, it is possible but doesn't happen to every engine!!

Hi guys, I have seen 8 X RB's with ceramic turbine failure, 2 X GTR's, 3 X R33 GTST's, 2 X R32 GTST's and 1 X R34 GTT and none of them had any ceramic anywhere other than in the cat.   There wasn't any in the turbine cover or in the dump or in the engine pipe, it was all in the front of the cat.  Blown there by ~200 cubic metres per second of ~600 degrees celsius exhaust gas, that's better than my Stihl leaf blower. :wassup:  

Maybe if you were spinning at the time and the engine turned backwards, you might get some sucked up into the manifold.  Of if you where starting the engine at exactly the time the ceramic failed and it coughed and ran backwards. :headspin:  

I don't think so, Tim :P

Well I have seen it happen on say 4-5 GTR's and a few GTS-T's.. dosn't always happen but IT DOES HAPPEN!!

Dosn't seem to happen to GTS-T's quite as much.. maybe due to GTR's having 2 turbo's and the manifold design etc makes them worse.

I will take photo's of the bore and the turbo, I though you of all people would have seen this one SydneyKid, but as you said you don't know everything.

There is always at least on exhaust valve still open it's a 4 stroke engine Roy.... so obviously the explosion is so great it sends the dust and bits up one of the open valves and into the cylinder..

Give me another explanation why there are bits of an "EXHAUST" wheel sitting in a bore in the garage at the moment.. and it got there just after it blew the front turbo up???

Over rev's and kaput.. really hoped it didn't happen to yet "another one" but the bore camera showed the truth.

All three front bores were scored.. one worse than the others.. but only the front 3, and it was the front turbo that blew?? coincidence?

People have argued this with us before.. it's not until they see it happen and wonder how there bore became so scored that they face it.

If someone can give me a good reason how the exhaust wheel magically gets into the bore other than that.. then by all means tell me!!!

But a missing exhaust wheel and the bore camera with bits of ceramic sitting in the bore on screen.. I can't see another reason.

With valve overlap and timing you can still get bits of ceramic into the combustion chamber. Exhaust gasses aren't continuously flowing out of the engine and in that short time when they are not you will get a neg pressure, backflow depending on manifolds, exhaust system, valve overlap etc.  So, it is possible but doesn't happen to every engine!!

Yes a believer! :P

Why do you people think they design split pulse manifolds.. the exhaust gases pulse.. so there is plenty of time for ceramic to get into your engine.

Yes, I believe you because I know about engines and have also read some articles on the subject and you are correct!!

Get some time up or know what you're talking about if you think it can't happen, otherwise people get the wrong info!!

I know of people who didn't listen.. then went and bolted new turbos on before checking the engine.

Wondered why after a few k's the car suddenly lost compression and some even seized there oil pump after the ceramic went past the rings and into the oil system..

It's like a cancer really :P

I will take some photo's when we get the head of the latest victim.. this car has a fresh rebuild 3000k's ago! and low k stock GTR turbo's. He wishes he listened to me when I said upgrade the turbo's to a non ceramic.

Well I have seen it happen on say 4-5 GTR's and a few GTS-T's.. dosn't always happen but IT DOES HAPPEN!!

Dosn't seem to happen to GTS-T's quite as much.. maybe due to GTR's having 2 turbo's and the manifold design etc makes them worse.

I will take photo's of the bore and the turbo, I though you of all people would have seen this one SydneyKid, but as you said you don't know everything.

There is always at least on exhaust valve still open it's a 4 stroke engine Roy.... so obviously the explosion is so great it sends the dust and bits up one of the open valves and into the cylinder..

Give me another explanation why there are bits of an "EXHAUST" wheel sitting in a bore in the garage at the moment.. and it got there just after it blew the front turbo up???

Over rev's and kaput.. really hoped it didn't happen to yet "another one" but the bore camera showed the truth.

All three front bores were scored.. one worse than the others.. but only the front 3, and it was the front turbo that blew?? coincidence?  

People have argued this with us before.. it's not until they see it happen and wonder how there bore became so scored that they face it.

If someone can give me a good reason how the exhaust wheel magically gets into the bore other than that.. then by all means tell me!!!  

But a missing exhaust wheel and the bore camera with bits of ceramic sitting in the bore on screen.. I can't see another reason.

Interesting...out of interest do the compressor wheels look healthy? But i suppose its the same debate, would parts of the compressor wheel make it thru the intercooler, thru the throttle body and then thru the inlet valve?!?!?!?!

Hi GTR- Ben, I am truely intrigued. If the engine is a single turbo (GTST) and is doing say 5,000 rpm, has standard cams, is a 6 cylinder 4 stroke of course, the numbers mean the ceramic has ~0.4 milliseconds to travel from the turbo to the bore. That's out of the turbine cover, up the inlet manifold and get past the exhaust valve while it is open and sucking (not exhausting). Part of that journey is against the exhaust gas pressure from the other cylinders. I could work out how many kph that is, but suffice to say it is way past the speed of sound.

I could see a GTR maybe doing it with aftermarket cams (longer overlap) at lower rpm's. A straight/shorter exhaust manifold would help. And if you heard the ping and shut the engine down, maybe.

Possibly that's why I have never personally seen it, we just don't have GTR's (or GTST's for that matter) with upgraded cams/manifolds and standard turbos. Plus they always let go at big rpm on the circuit, at full throttle and the drivers don't back off either.

Very interesting...........

You are right, ceramic is nasty stuff, makes great grinding paste. :mad:

Well it's usually on GTR's with stock cams etc.. just intake, exhaust and around 1 bar.

I don't see it on the GTS-T as much, I think because they don't handle boost as well that would pop the turbo, and being a single turbo. Most people upgrade to a VG30 or similar and run less boost.

What about taking into account the speed the turbine wheel is spinning at when the engine is doing 8000rpm? 10-50X more?

The last car wasn't under load when it blew though.. so I would say boost wasn't that high it was purly revs. (2WD clutch drop in snow..)

We don't keep the stock turbo's with mods over filter and exhaust.. but there are still quite a few GTR's down here getting round with stock turbo's. We did push them out to an 11.6 on one GTR before they popped (this was the first time we saw contamination and were very confused)

I am actually scared to drive a GTR with stock turbo's these days.. I just see $$$$.

Any other ideas on why.. ?

Well it's usually on GTR's with stock cams etc.. just intake, exhaust and around 1 bar.

I don't see it on the GTS-T as much, I think because they don't handle boost as well that would pop the turbo, and being a single turbo. Most people upgrade to a VG30 or similar and run less boost.

What about taking into account the speed the turbine wheel is spinning at when the engine is doing 8000rpm? 10-50X more?

The last car wasn't under load when it blew though.. so I would say boost wasn't that high it was purly revs. (2WD clutch drop in snow..)

We don't keep the stock turbo's with mods over filter and exhaust.. but there are still quite a few GTR's down here getting round with stock turbo's. We did push them out to an 11.6 on one GTR before they popped (this was the first time we saw contamination and were very confused)

I am actually scared to drive a GTR with stock turbo's these days..  I just see $$$$.

Any other ideas on why.. ?

The turbine blades should never exceed the speed of sound, the mini sonic boom would destroy them. So I don't think speed is the answer. Maybe they let go big time and then shed little bits of ceramic over the next few times the engine is started. When you fire it up to put it in the workshop, on the trailer, stuff like that maybe would be a problem on a GTR.

It certainly isn't a problem on a GTST, I have seen one driven 200 k's home after a turbine failure, it only had ceramic in the cat. I know because we took the head off while the turbo was being done and did some porting and polishing. It was clean as a whistle inside.

Bottom line, I don't know :)

We make sure when we pop them to shut them off straight away and get a tow. Just incase the turbo did go through the engine.. every second = major damage. :)

So it all happens at the same time in one big boom.. wheel is there the first second, next the engine is full of abrasive crap..

It's just one of those things.

And for those of you with stock turbo's reading this.. be careful. Please have your engine checked after you blow a ceramic turbo. :D

I just pulled off both turbos off my r32 over the weekend and need to find out what spec these actually are. They are NOT! N1's as I was told they were and this car had been running 1.3 bar for who knows how long. The bearings are bushes and they have ceramic turbine wheels that are in as new condition. Just the bushings are worn.

I need to find out what these are off. An r32, or a r33.

Here's the specs: Compressor A/R 42, Turbine A/R 64

BB 0102J, 14411-24U10, 466089-6C

Any help would be excellent as I'm deciding what to do with the turbo's.

Cheers.

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