I need help!! Info on a turbo!!

[ct-12b]

Hi i just joined this forum for the sole purpose on getting some info on a turbo i just got my hands on.

I have a ct-12b turbo off a usdm supra. The questions that i have are as follow:

1.- The turbo has several places where it seems it has outlets and intakes... Two of them are single and are the same on both sides and one of them seems to have a screw on nipple type and one that seems to connect some type of hose. I need to know what these are. I take it they have to be oil inlet and outlet and i take it one of them has to be water. I need to know which is which!!

2.- What is the best efficient range of boost that this turbo is capable of?? By this i mean, how much boost can it produce and still be in it's efficient range.


Please, i will appreciate honest answers, I DO NOT OWN A SUPRA, I just got this turbo because it was available to me and am planning to use it on a 1.6 SOHC Honda engine but am lost about what these ports are on the turbo. I am not capable of posting pics on forums but if it's necesary I will email pics.

THANKS IN ADVANCE FOR YOUR ANSWERS!!!

Jack

[Bill UK]

Not sure about the CT 12B Turbo, I would have thought the connections would be similar to the CT26 Link Photo below is the CT26

[ct-12b]

Thanks for the very helpful info!! I knew that there was someonde bound to answer at least one of my questions. Thanks a lot !

[MA70-3.0GT]

Not wishing to rain on anyone's bonfire but wouldn't a turbo that size be a bit laggy on a 1.6 motor? I only say this because there's a fair amount of lag even with the exhaust gasses of a 3.0 flowing through so surely an engine just over half the size would produce not much more than half the essential exhaust gas to spin the turbine, at any given RPM?

I'm not saying it won't work because I don't profess to know everything about turbocharging, but my gut feeling is that a large turbo on a small engine would have major lag & possibly even struggle to get up to a speed where it can produce enough boost...
On the other hand it could well be that it will have a lot of lag (that's a given) & then when it does come on song it could be a HUUUUGE amount of fun indeed.

I for one will be interested to hear the outcome of your project & hope you'll post back about it, you certainly would seem to have mucho cohones to be trying this and I hope it goes to plan.

Best of luck, Dan.

[ct-12b]

Well, let's think about it...
1.- The ct-12B is smaller than the ct-26
2.- The ct-12b is utilized in a six cylinder, TRUE, BUT 3 cylinders make it spin, the other 3 make the other turbo spin; it'll go into a four cylinder, therefore an extra cylinder is involved.
3.- The ct-12b is actually a bit smaller than a gt-28. I have the comparisson specs but i suck at posting pics.

So My guess is... it'll actually be a good turbo for a 1.6 with 75.5mm bore and 90mm stroke and a 4.25:1 final gear ratio to reduce any potential lag.

Did I make sense??

[MA70-3.0GT]

Right, thought about it... Yep, perfect sense. The ct-12b is from the twin turbo then? I was under the impression that the turbo you were talking about was simply from a USDM 3.0 turbo but it's actually one of the units from the 2.5 TWIN-turbo isn't it?

In that case then I think you'll find very little problem with spool times or with the capacity of the compressor to produce sufficient boost for your engine (having effectively come from a 1250cc, 3cyl application). It's all in the interpretation see, If I'd known it was a tt blower I'd have kept my big yap shut (or simply put the last bit about posting back the results, speaking of which once you're up & running try & get a video on youtube or similar & let us know where to find it, I wanna see!!!).

[ct-12b]

Well... i have been searching info on the usdm supra and it seems that it uses the ct12b BUT I believe that the only difference between it and the japanese version is that the Jap version has a part inside the turbo that is ceramic coated and the us version is of another material which is more durable i believe. I rather not say in order to not sound foolish but i beleive that's the only difference.
I also think that the 1jz uses the ct-20... not really 100% on that. But yeah... i think it's gonna be a good match for a 1.6

I've read that these boost 10-11 lbs stock and have been pushed to a max of 18lbs on the supra... so my target 15lbs is definitely doable from my point of view.

I too am not a turbo know it all and am doing my research as i go along. As for video... consider it done... I'm planning on documenting my build covering every detail with pictures and having a video of it up and tuned!!

[MA70-3.0GT]

Cool, I'll look forward to following this. It's not too often these days that someone does something really different.

I'm not sure of the differences between the Jap. & U.S. versions of the turbos but the alternative material you're thinking of could well be Nikasil, a hard coating commonly used on 2-stroke bike engines, it's that good that a couple of thou coating is put straight over an aluminium cylinder bore & it's then capable of outlasting a steel liner!!! In fact on the bike barrels, the only time it needs to be bored & recoated is if the engine siezes & the piston melts into it, they just don't wear out.
Something similar was also used on Wankel rotary engines to avoid the rotor seal/housing wear & melting problems they had (A groove was machined into the housing & a band of molybdenum alloy, I think it was known as Molykote, was used as the sealing surface along with Nikasil rotor tips.)

Either way, if your turbo has either one of these treatments I think you're onto a good thing! I take it you have the original wastegate actuator fitted to the turbo at the moment, if so then I believe the boost can be taken up from the stock setting by adding a measured shim to the assembly. Or you could just use a bleed valve to "trick" the wastegate into opening at say 15psi. The shim method is in a thread on the Mk3 area IIRC.
If you don't have the actuator, or are going to replace it then you can usually get uprated units that operate at a higher boost pressure anyway, and if you're building from scratch a new actuator would look nicer IMO (depending on how visible the turbo is in your engine bay).

[ct-12b]

Hmmmm interesting facts about coatings. But what i meant was the turbine wheel material in the usdm model is longer lasting than the jap. That is what I read. And yes i have the stock actuator/wastegate but I'm going with an external Tial unit for the extra lbs. of boost.
I've read that these turbos are quite good, they're made by Hitachi and are just a bit smaller than the gt28 so I guess my little motor will be a spicy little devil!! hahhaha on and the goal will be AT LEAST 200-250whp. I think "TOPS" for my setup will be 300whp!