Someone please set me straight Re: stock turbo

[33HKS]

Hi all,

Could someone please give me some reliable info on the materials used in the stock turbo on my Series 1 R33 GTSt?

I have read many posts and have looked at many site all over the net and i get conflicting stories everywhere.

I have heard that series ones have steel turbines on one page and ceramic on the next, also max safe boost levels seem to fluctuate between 10 psi and 14psi.

Someone please help as i would really like to know for sure.

Thanks

Gary

[32godzilla]

Ceramic turbos are used on all models of Skylines, max safe boost for good turbo life is 12PSI. Although I've heard of many people running higher than this but 12PSI is the max suggested boost level.

[GTS-t VSPEC]

32godzilla, Not quite true, there are some Skylines (R34's) that have plastic turbines.

Safe boost is a difficult question. Stock boost is safe, anything above that can reduce the lifespan of the turbo. Most people will run 12psi quite happily. I have run up to 17psi in mine and it's still attached:D

[rs73]

Both S1 & S2 R33 turbos use ceramic turbine. However it is said that in S2 the compressor wheel has been replaced by plastic (polymer?) in order to reduce weight and allow the S2 turbo to spool up faster & earlier. Exhaust wheels are still ceramic as plastic won't stand the heat.

[BOOSTD]

I was under the impression R34 had a plastic compressor also. I think the better the intercooling the higher boost that can be run safetly. Most turbo failures I have seen and experienced come from very high speed 105,000 rpm plus and also the onset of detenation which causes the turbine to unbalance, touch the exhaust housing and snap off the shaft. Extra heat in the exhaust housing causes the metal to expand and reduce to turbine to housing tolerance. I am under the impression boring out the turbine housing slightly(0.5mm) will vastly improve reliablity and only slightly increase lag. I haven't seen any actually come un-glued as some people put it.

[2rismo]

Many many many gts-t's have had the turbine wheel break up or fly off entirely and play friendly-like with their catalytic converter.

This is because of the way in which the ceramic wheel on the exhaust side is bonded to the shaft, (some kind of epoxy??). It either delaminates and detaches from the shaft or bits fly right off and imbalance the turbo dramatically. **

[browny]

Agree with GTS-t VSPEC. Since each turbo's boost threshold is unique the only way to find out is trial and error. I have heard reports of them failing at stock boost in rare cases.

[Guest INASNT]

noooooooooo not another 1 of these threads

[33HKS]

Thanks for the info guys, i will keep boost below 12 psi for now

Gary