[MidNite-D]

Posted this on the other forum but haven't had a defintive answer yet so:

I know that DET is the main cause of engine failure (besides excessive heat or lack of cooling), but is it also the main cause of turbo failure. I'm asking because when I had my car checked for fuelling, it was run at the boost settings that it came from Japan with, i.e. just over 1.2 bar. It had no DET at all so I was quite happy with that outcome but I have only been running it on low boost as I don't know if the turbo's have been uprated and don't want to run into any problems.
So my question is if I have no DET will I be ok running the car at the boost that was being used when the fuel check was done (High Boost) or do I have to get the turbo's taken out to check if they have been uprated so I don't blow them up. Its doing my head in so I would be grateful for any light that could be shed on this subject. Thanks

 

[R33_GTS-t]

Which GTR is it.

The R32 and R33 stock ceramics are reliable up to 1.0bar and the R34s up to around 1.15bar.

It's a difficult question you ask. Taking them out to have a look is almost as costly as replacing them with steel items if a garage is doing it. If it came with 1.2bar set, I'd assume it's safe but the choice and risk is yours. No good answers, sorry.

What kills the ceramics is the torque imparted on the blades at high boost. Det doesn't help though.

 

[MidNite-D]

Thanks for the reply R33-GTS-t, its an R33 BTW, I think you understand my dilema, the warning boost is set at 1.3 Bar and as you rightly point out you would think that it would be safe to run at that level of boost, but as you said there is a risk attached. I am trying a different tack and have asked the company that helped me source the car to try and get in touch with the previous owner in Japan and ask them the question. So I guess its low boost for a while yet.

As a seperate but connected question, what are the signs if any of turbo failure? Thanks!

MidNite

 

[Warpspeed]

There is no definite answer. Higher boost means higher turbo shaft Rpm, and any ceramic turbo will eventually fail if you keep gradually increasing the boost in small steps.

But there is no real way of knowing at what boost, or for how long any particular turbo will last before it suddenly bursts the ceramic turbine wheel.

General opinion seems to be that 1.0 bar is absolutely 100% safe, and 1.2 bar is probably o/k. Anything more than that starts to become rather risky, some people are lucky, others are not.

The signs of a single turbo failure will be sudden and complete loss of boost. The car will be completely gutless to drive, there will be absolutely no doubt about what has happened when it occurs. The good turbo just blows air backwards through the compressor housing of the dead turbo, so there will be a MASSIVE boost leak and almost no measurable boost pressure.

The major worry is not the dead turbo, but when a turbine wheel explodes, it can shoot bits of very hard ceramic material back into the engine past an open exhaust valve like bullets. These ceramic chips have been known to do massive damage to one or more pistons or cylinder bores.

 

[MidNite-D]

Thanks Tony, I am not going to chance it at the moment and will just run low boost until I can find out more, its just hard to have the potential and not be able to use it without the fear of the turbo's going pop.

MidNite

 

[raz0r$harP]

With the ceramic wheel delamination is typically brought on by high temps. They will rise when you are running too much boost through them or it is being pushed for extended periods (e.g. doing some track work).

Something like taking it down the 1/4 mile would be less likely to bring on failure as it's only being pushed for v.short bursts of time.

 

[kingsley]

Aside from the things already mentioned here, oil starvation, often caused by blocked oilways due to not following proper cool down procedures, also kills turbos.

 

[Hugh Keir]

How do you know you don't have any DET

 

[MidNite-D]

Thanks for the answers guys, it really is helping me get my head round a few things. I know about the cool down and warm up, can't drive the car fast on normal roads as suspension is so hard, so by the time I can open it up the oil has reached operating temp, about 80C and never goes much above that even when I run it hard. I've got a turbo timer as well but again the drive home is quite slow so it gets a chance to cool down before I get there.

Re the Det Hugh, when I had the car checked for fuelling and dynoed at The Racing Line, Matt took it up to 7649 RPM, had the Det cans on and he said there was no Det at all. He also pointed out to me that the air/fuel ratio was about bang on as it ran 10.7:1 at those revs, which he did say was slightly rich but that protects the engine helping to keep it cool.

I'm learning slowly, was reading the forums and finding out as much as I could before the car got here but still got a lot to learn.

If I have got any of these points wrong or am getting the wrong end of the stick please tell me. Thanks again for your comments.

MidNite