st185 jdm compared to the usdm 3sgte?

9

903SGTE

New member
whats the diffrence between the jdm and usdm 3sgte? i have a 1990 st185 and was thinking of installing a jdm motor. what to i need or what needs to be done to get this swap to be done correctly?
 
R

RIalltrac

Active member
theres really no difference, the biggest difference lies in the ecu and the harness. The harness is set up for rhd while the usdm is setup for lhd. Just enters the cabin on the other side of the car. The only thing youll notice about the two engines is that the head on the jdm isnt setup for egr equipment. Other than that the engine itself is rather identical.
 
9

903SGTE

New member
so can the jdm be put into the usdm car? harness and all?? also what about the trans?? can i use the engine and trans in my 90 alltrac? is the gearing between the front diff and rear diff going to be the same?
 
9

903SGTE

New member
so the trans will work with my rear end? the ratio between the front diff and the rear diff are the same? also what about all the accesories on the engine? is the location of the ps pump and alt. in the same place or do i have to swap over my mounting brackets so i can move the accesories to the right location? thanks for the help.
 
R

RIalltrac

Active member
903SGTE":c5hznbir said:
so the trans will work with my rear end? the ratio between the front diff and the rear diff are the same? also what about all the accesories on the engine? is the location of the ps pump and alt. in the same place or do i have to swap over my mounting brackets so i can move the accesories to the right location? thanks for the help.
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If you have a jdm engine the only thing you would need to make it work in your usdm alltrac would be the usdm wiring harness, the jdm one goes into the cabin on the other side of the car, so its not exactly set up to go the way you need it to go. Otherwise, its a complete plug and play setup.
 
K

klue

New member
doenst the jdm one has higher compression, cermaic turbo, no egr, egt probe on downpipe, fuel and timing maps are more agressive, harness is differnt
 
C

Conan

New member
klue":2ccji744 said:
doenst the jdm one has higher compression, cermaic turbo, no egr, egt probe on downpipe, fuel and timing maps are more agressive, harness is differnt
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:D yeah, also anti-lag, launch control, water injection, forged internals, triple plate clutch and fuel cut at 32 psi :evil:

Seriously though, ceramic part is true. Everything else was either covered by the ECU part or not true.
 
G

gt4tified

New member
I'm not too sure but I think/hear somewhere that the JDM ecu's were programmed for a bit higher (or was it lower?) octane content pump gas than the USDM....can anyone confirm this?
 
C

Conan

New member
gt4tified":w6726qsg said:
I'm not too sure but I think/hear somewhere that the JDM ecu's were programmed for a bit higher (or was it lower?) octane content pump gas than the USDM....can anyone confirm this?
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Yes, more aggressive timing due to higher octane, it's still in the ECU though...
 
G

Gary

Moderator
The JDM transmission has electronic speedo sensor.
The US one has mechanical speedo sensor (cable driven)
However, you can swap the electronic sensor on the JDM with the mechanical sensor from your US one.
 
9

903SGTE

New member
thanks for all the help guys! i think im going to order the jdm st185 engine! is there anything i should do to the jdm engine before installing it in the car? someone a while back, i think on the supra forum, mentioned that when they install a jdm engine they always replace the engine bearings due to the salt water during the transportation eating away at them?? does that sound right? thanks again!
 
J

jlspec

New member
Since the engine is out, Get a performance clutch, change all hoses and gaskets (The head gasket is optional depending on what your planning),Clean the dam thing, and you might want to get the transmission check or replace to save you Major headaches later on.
 
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