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Discussion Starter · #1 ·
Will 2JZ Jspec turbo's work on a 1JZGTE ? If not can I use the OEM turbo manifold on the 1JZ and fit better/bigger turbo's on it and custom plumb to the intercooler? Would everything else work as far as prespool, actuators and so forth??
 

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SF in my veins... sigh
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Nope... CT-12b's use an entirely different flang than the CT-12a's.

And the 2J exh. ports are spaced differently than the 1J's so you can't use the 2J exhaust manifold either.

Despite the similarity in name... the CT-12b's are quite a different animal.

You could put alternate turbos onto the stock manifolds with an adapter plate... you'll need to solve the wastegate issue too (either plumb your own or use internally gated turbos)
 

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Discussion Starter · #5 ·
Yeah I hear ya. I just like the low end responsive twin turbo setup. I actually have a HKS wastegate, Blitz BOV, haltech e11, HKS twin ignition, all brand new for single upgrade. I had it all for my 13B that I was going to single so it would be easy except I need an exhaust manifolf and turbo. Where can you buy just a manifold from. I can find a turbo.
 

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upgrade your twins with bigger steel impellors...
 

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SuprAng said:
upgrade your twins with bigger steel impellors...
Prob is in finding steel internals that will fit the CT-12a's in north america. There are some options but mainly from turbos sold only on overseas cars.
 

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cant just go to a turbo shop like you would with a ct and tell them to put a bigger wheel in?
 

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SuprAng said:
cant just go to a turbo shop like you would with a ct and tell them to put a bigger wheel in?
I went down that road... cost to do it and options made it not worth it. Cherry Turbos explored a ton of options for me and in the end suggested it would just be cheaper to replace them with something else than go through the work. They are just too small to leave many options available. That and the bearing design I THINK was an issue.

Now the Aussi guys use internals from Starlette turbos I believe... works quite well from what I read on their lists. Also Adi (in the UK) got some CT-12a's hybrided but the shop that did it isn't talking ;) Looks to be a nice job though (props Adi) but no one in the US to my knowledge has come up with any cost effective way to upgrade the 12a's. Too bad too... I thikn it would make a killer 400hp setup if they could handle higher boost. I forsee someone coming up with a CT-12b adapter kit... I am very suprised it hasn't been done already.
 

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hrmmm, i remember reading somewhere that the 1ggte steel turbos will bolt right on? is this accurate?

Ang
 

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Haven't heard that one myself so I can't confirm... but I am 95% sure they are even smaller than CT-12a's as they were intended for a 2.0 L engine.

Edit:
Here it is... I knew I filed this somewhere...

Comparison of the CT-12 with the CT-12a...

http://www.toymods.org.au/1G_vs_1JZ/

As small as the CT-12a is... you'll be amazed at how much smaller the CT-12 was.
 

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I've just finished bolting a pair of Jap spec CT-12b's onto a 1JZ-GTE... entire conversion was done with the motor in the car, so it was a proper c***....

I'll let you know more when I've sorted out the ECU side of things... the ct-12b's overboost, apparently they'll top out at ~16.5psi...

Basically... summary of the conversion... Toyota changed pretty much every measurement by about 7%... just enough to make you have to work to make things fit :)
 
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you could put the mkIV turbos on the 1jz, you'll just have to make an adaptor plate for each one. its not like its THAT big of a deal.
 

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what you need to fabricate is a spacer for between the front and rear turbos, i did it with a single plate approx 5mm wide, if i was doing it again, i'd make 2 of them half the size... just to even the length of the studs...

to get the turbos onto the half manifolds, you need to drill out the holes on the manifolds a few sizes, and i chose to port match the manifolds to the turbos, but you don't absolutely need to do this...

oh, and the support braces... the front one you need to bend the ends on a little, less than 5 minutes worth of work.. the end one is a little more difficult, and i'll look into that when i get the car up on a hoist and can move around under there a bit more easily...
 

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Question I have is: Does the ct12b bearing housing bolt to the ct12a exhaust housing? If it does, does the ct12b turbine spin freely in the ct12a exhaust housing? I think you guys know where I'm going with this...

-Brendan
 

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Discussion Starter · #19 ·
FIL

Thanks for the help!! I'm very interested in a dyno sheet when you get it all done. You have to post it.
 
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