They are discussing whether the Jap import manuals and autos have the same size turbo.

 

Hope this link works :-

http://network54.com/Hide/Forum/message?forumid=70520&messageid=1005564159

 

No explanation yet as to whether they are the smaller auto turbo, or the larger manual one. Given that the power outputs are less important to the heavilly restricted Jap market it may be possible that (it's all bull) or they use the smaller turbos for greater low down ooomph.

FYI the part numbers are different;

 

Manual 01/90 on; 14411-40P01 (left turbo)

Auto 01/90 on; 14411-40P06 (left turbo)

 

AFAIK the difference is in the A/R ratio of the compressor blades, externally they look identical (probably leads to all the confusion).

 

Az

My understanding exactly, but it's an interesting theory of theirs.

 

Facts and data will tell in the end ...

Andy,

 

My understanding is the same as you, that the turbos are different with all Autos being smaller. This gives the auto quicker spool-up and lower torque to compensate for the box, and giving similar acceleration to the manual. Unfortunately Nissan have taken away the Fairlady Z pages from their site which had the technical information, but I think I remember seeing the Auto giving out slightly less BHP than the manual, which would tend to confirm this.

 

With you participating in the conversation over there, is it worth asking about Ceramic Impellers being fitted in (some) Import Turbos? I have a 7.1994 manufactured 2-seater TT, and I am being told by my garage that I have the ceramic type. I know the Skyline had them fitted for a couple of years, but there is some question about the Fairlady Z (although I believe my car is stock). Appreciate it if you could.

Thanks, Geoff

Hows this for a bit of information ?

A/R is not a charateristic of compressor or turbine wheels but describes the relation to the area of the outlet compared to the radius of the inlet on the compressor housing or vice versa on the turbine housing**

 

The differences in turbos are.....

Autos have 0.54 a/r turbine housings

Manuals have 0.63 a/r turbine housings

 

Which means that the threshold (switch on point) of the manuals is slightly higher and they perform higher up the rev range.

 

Note that we've seen quite a few original manual TT's with 0.54 a/r turbine housings which means either some production line runs were with the .54's or the turbos were rebuilt in japanland and turbo rebuilders stockpile the .63 housings.

 

So if you've got a quick manual tt and you are pulling good dyno figures there might be something in that turbine housing.....

 

**This is also why buying a hyrbid turbo can be the biggest waste of money and one way path to engine failures.. people often stuff a T3 compressor in the stock housing without thought - and then wind up the boost, the diffuser area and therefore a/r is shot to hell, the air coming off the compressor doesn't get a chance to smooth out and has to squeeze back out.. nice superhot air = kaboom to engines.

 

:-)

 

Rowan

How can you tell what ones you have on? I am begining to think that my car has not got the original turbos on. Maybe they have been reconned. There is a gap in the recepts between 95 and 96. If they are the original ones they have done 144,470 miles and the seals arent even leaking.

 

PS. KIWI_Z my friend went New Zealand and a billiards Competition and ended up getting to the Semi Finals of the New Zeland Billiards Open. COOL

 

Stuart

They are different, according to Mr. Hutton(I was flicking through my book last night) they are T2/2.5 Turbos

 

Somebody correct me here, but I read that the Skylark Turbos are used on the Man Z...T28???

 

Which is what Warren is running on his car, but he reckons that his are upgraded? I think they are standard???

 

Anyone else know about this?

 

All IMHO of course

Just to make things more confusing

 

What about pre Jan 1990? (mine's a J-Spec 1989 auto)

 

 

 

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I think T28's are used on 200sx's. Don't ask me which model though ....