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The US Ecu will work with the JDM motor as long as the wiring harness is USDM as well. I have the same thing right now. my motor and tranny are JDM but i am running a USDM harness and ECU, one thing to remember is that you will have to change out the injectors to the USDM injectors because the plugs are different on the JDM spec. And the stock twins are smaller on the JDM motor, therefore you will have problems bolting the downpipe to the JDM twins. i had to ditch the JDM twins and injectors for the USDM setup.

Looks like you are going the same right as me right now. What exactly are you doing with your car.
 

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im running a US harness with JDM injectors, jdm turbos, custom downpipe, jdm ECU, everything working fine, i dont see why people think this wont work...i got my car running perfectly no problems....only thing right now is turbo seals but ill be upgrading shortly eneough...im also using the 5spd btw...

Ben Y
 

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Sins4u33 said:
im running a US harness with JDM injectors, jdm turbos, custom downpipe, jdm ECU, everything working fine, i dont see why people think this wont work...i got my car running perfectly no problems....only thing right now is turbo seals but ill be upgrading shortly eneough...im also using the 5spd btw...

Ben Y
Great to hear it worked out :bigthumb:. Any check engine lights? Is the maf plug just left unplugged?

~Kevin
 

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Ben's car is running like a champ!
 
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you'll need the us maf, us injectors, us resistor pack, and us harness to run the us ecu. maybe a s-afc to make up for the air flow difference of the turbos and cams.
 

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Discussion Starter #8
MKIV4EVER said:
The US Ecu will work with the JDM motor as long as the wiring harness is USDM as well. I have the same thing right now. my motor and tranny are JDM but i am running a USDM harness and ECU, one thing to remember is that you will have to change out the injectors to the USDM injectors because the plugs are different on the JDM spec. And the stock twins are smaller on the JDM motor, therefore you will have problems bolting the downpipe to the JDM twins. i had to ditch the JDM twins and injectors for the USDM setup.

Looks like you are going the same right as me right now. What exactly are you doing with your car.

so did you just buy a jdm motor with cut harness and add the usdm 6 spd harness on their? can i do it that way? i have an auto usdm ecu and i dont want to have to buy another ecu. i dont mind buying a harness because it is easier to find a cut harness motor than a full harness motor.

the motor i was buying was auto jdm with full harness. i didnt get it though because of harness issues (couple clips broken).

i can get usdm turbos no problem. my friend will give them to me for free. i allready have tt fuel pump and maf aswell. all i really need now is the motor and us harness which i will get soon i hope.
 

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Discussion Starter #9
Sins4u33 said:
im running a US harness with JDM injectors, jdm turbos, custom downpipe, jdm ECU, everything working fine, i dont see why people think this wont work...i got my car running perfectly no problems....only thing right now is turbo seals but ill be upgrading shortly eneough...im also using the 5spd btw...

Ben Y
but will jdm harness work with usdm auto ecu? its the opposite. im also running 5 spd.
 

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Urban Customs said:
so did you just buy a jdm motor with cut harness and add the usdm 6 spd harness on their? can i do it that way? i have an auto usdm ecu and i dont want to have to buy another ecu. i dont mind buying a harness because it is easier to find a cut harness motor than a full harness motor.

the motor i was buying was auto jdm with full harness. i didnt get it though because of harness issues (couple clips broken).

i can get usdm turbos no problem. my friend will give them to me for free. i allready have tt fuel pump and maf aswell. all i really need now is the motor and us harness which i will get soon i hope.

I bought my motor with cut harness, so bascially my motor and tranny are JDM, but my ECU, wiring harness, turbos, and injectors are all USDM.

You can still use the JDM turbos but you will have to significantly modify your downpipe or weld a smaller flange since the JDM turbos are smaller then the USDM. I didnt want to go this route because it takes time and i wanted my car out of the shop, so i opted for the USDM turbos.

But since you have the JDM motor and i assume you have the tranny (which doesnt really matter in this case) you will be fine. Just get the USDM auto harness, and since you will be getting the USDM turbos for free, you shouldnt have a problem. One problem i ran into with my injectors was that the USDM harness plugs would not plug into the JDM injectors, so i had to get the USDM injectors, i dont know how Sins4u33 got it to work, maybe he can further elaborate on this.

Wish you the best of luck.

Remember patience is the key to all success...........which i dont have :bigthumb:
 

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is your motor definitely from a supra and not an aristo? if its from a supra you _should_ be able to use your jdm harness with a US ecu after a bit of rewiring. if its an aristo ecu it will involve considerably more rewiring cause the body connectors are different.

but again you'll need to put in the US maf, injectors + resistor pack. it _might_ be worth it considering the cost of a US harness, but that's up to you.

most of the rewiring involves running wires to a MAF connector (which you will need as well, unless you run a VPC etc). it will involve adding/swapping 2-3 pins on the ecu connector on the harness. i think you will also have to run a new wire for EGR if you want that to work properly too. basically just compare the pinouts for the jdm ecu (available at mkiv.co.nz) and the pinouts for the us ecu (mkiv.com)

or you could get a jdm ecu + map sensor for next to nothing. get a fuel controller + us spec injectors + resistors and with tuning you should be up for as much power as a us ecu would provide
 

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Discussion Starter #13
ok so here is my update.



after i did some research. it seems my best bet is go buy a jdm motor in the area and i can go pick it up for 2100. im going to go buy a new harness from toyota which costs 800. im going to use my friends us spec turbos and i allready have us spec rmm downpipe and auto ecu (which should plug in to 6 spd harness and work). i also bought the 6spd pulley tension dampener system to swap over to the auto motor. i bought brand new tt fuel pump and whole bracket assembly. hpf intercooler is on the way aswell.

when i put the whole 6 spd harness on the jdm auto motor will every clip just plug in? do i have to do any mods?

other than that basically all i need now is the us spec injectors, fuel rail (but i dont see why i cant use jdm ones?)


thanks
 

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Discussion Starter #15
Blk96SupraTT said:
US injector size is 550cc verses JDM are 440cc

could i just use the prior jdm clips on motor and splice them to my 6 spd harness. that way i dont have to waste money and get the usdm fuel rail and injectors.

so basically i want to run usdm turbos with jdm fuel system. is that possible. or should i just stay all jdm and modify my downpipe?
 

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Discussion Starter #17
Boostinhard said:
the turbos will outflow the jdm fuel rail and injectors.

so either i stay jdm ecu and turbos and harness. or go us everything?


also i read on club nat that if i go jdm harness i need to extend it? what does that mean?

i think im just going to call curt monday and order a new 6 spd harness.
 

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Yo man how is your project coming along. I went to the shop to check how my car was doing. They are pretty much done with my conversion and i should be able to get it back from them by next week. Once i get it back i will post pics of the completed project.

One thing they told me was that since the JDM motor lacked the EGR, you will constantly have the check engine light one. No biggy, just take the bulb out, which i am planning on doing, give us an update.
 

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Sherbaz from here on the forums is a great guy, send him a pm and he will sure take care of you no problem! I got my motor from him! Great guy!
 
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