grumpi300

iTrader: (1)

still looking for an answer after days and night of endless searching.

obd2 sounds like the way to go since its way more advanced as far as monitoring goes. standalone's also do a big help. still can pass smog when hooking up obd2 port. only 1 question left.

obd2 lexus sc300 ecu is for n/a 2jz. i understand this much. i also understand you can add a standalone to modify if you want to add a 2jz-gte. or even want to tune. but i know that a standalone will never compare to the stock ecu of a car that has had millions of dollars and ton's of time invested in it to run the perfect ratio of basically everything.

so not only will the 2jz'gte's twin turbo's be in my car, i'm also wondering if the toyota supra ecu can be converted to the lexus sc300. the reason i asked is because if you have a n/a ecu from the lexus with a twin turbo'd engine, there's gonna be things off. and obviously the standalone can cover but there will always be missing spots or glitches.

now the reason i want to know the answer to this is because i read that some ecu's retain the information of what car its supposed to be in. for instance, if i put the toyota supra ecu in my lexus, then come time for smog, they hook up the obd2 port, BAM!!! i fail for the ecu saying its out of the wrong car or something. or the vin on the car doesn't necessarily match the vin that's engraved in the ecu.

so my question is this, "putting time and money aside, is it possible to put a obd2 supra ecu in a obd2 lexus and still be ok with emissions?"

here is where i got some of my information from if any of you are interested...
http://www.supraforums.com/forum/sho...D2-ECU-Upgrade
http://importsnc.com/forums/car-tech...ps-toyota.html

sj408

iTrader: (6)

Not sure about obdii, ali just put a gte ecu in his car and im gonna be done with mine soon as well. Not sure about smog yet though

stockhatch

iTrader: (12)

Haha, you found my 2GS thread on INC. Nice

It all boils down to this:

1.) The donor vehicle must be the same year or newer than the vehicle it is going into.
2.) From all of my research on the matter, the Supra ECUs do not store VIN information
3.) The SC and Supra share a common engine family, so the GTE swap should be perfectly legal provided all emissions components are intact and functional.
4.) The car should pass an OBDII plug in test provided everything is in place and properly working.
5.) There is going to be some wiring involved.

Ali SC3

iTrader: (10)

I have sort of skipped over the whole odb2 thing up until now because i don't have a way to test it.
I have been thinking about it though as I do get asked from time to time, so if someone wants to do it I will help them out wherever I can.
I believe it can be done, and it may even be easier than the odb1 gte ecu mod, which is already easy enough.

I am assuming you would start with the odb2 vvti GE harness that is already in the car, and these use a hotwire maf, with the wastespark vvti coils and dh61 ignitor.

the supra GTE vvti odb2 ecu uses a hotwire maf, the same coils, and the same ignitor as the vvti GE.

I'm not sure if the mafs are the same, if they are not you can repin the stock maf connector to the GTE maf, then that is mostly what is going to need to be adressed, because the ignition is already the same so you dont need to add wires for that at least like you would on an odb1 ge harness.

as for the odb2 funcionality, i would guess that it would work without moving any pins, toyota usually keeps diagnostic stuff in the same spots, as my odb1 aristo ecu reads out the codes just fine on my odb1 ge harness. Since its odb2, i would recommend using a USDM GTE ecu, as the best chance for all the odb2 stuff to work. The JDM could work too, but i dont know for certain either way but the USDM will have the better chance. a look at the pinouts will tell you what you need to know.

so in summary, if the mafs do turn out to be the same or at leas have the same connector, and all the odb2 stuff is in the same place, it will be a matter of swapping out the maf and the ecu. sounds too good to be true, but thats basically what you do for the odb1 + the ignition stuff.

grumpi300

iTrader: (1)

Thank you so much stockhatch!!! You are the best!!! I now have a new goal.
So I now know I want a 96 or 97 Lexus with a 97 2jzgte non vvti with a 97 Toyota supra ecu!!! I now know its pissible.
Alisc3, I'm really not interested in the vvti. I know its more power but its also more complicated. Being as I doubt I can even handle the power of a stock 2jz I don't want to mess with all that. My main priority is being able to put a twin turbo 2jz into the Lexus with the supra ecu and still passing emissions. Vvti is more complicatd like you said and I really dont want to deal with that. Not yet atleast. Thanks tho.
So now that I have this goal, I know what to look for, and am gonna start saving up. Thank you stockhatch.

grumpi300

iTrader: (1)

But ali you did help out. Thank you for all that usefully information. I will keep that in mind when I do the swap.
So considering you both did the swap already, how does it run and feel? If youve done any mods or standalone how easy/hard is it and does it hurt any for emissions?

blk&blu*j

iTrader: (1)

Not to throw a wrench in your plans but a jdm 2jzgte is on a map sensor and it also has no EGR valve. unlike USDM and USDM 2jzgte is on maf as well.

Just FYI.

grumpi300

iTrader: (1)

I wouldn't get a jdm supra engine. I read somewhere a long time ago that they are made nether usdm. That jdm ones are softer internals such as pistons and rods. I don't remember the ling but yeah. :/ is there any truth to this?

blk&blu*j

iTrader: (1)

You got to love the internet it is such a great tool but also your worst enemy ^^^^^^^^^^^^ I call B'S!
The major differences are 440 low impd to 550 high impd injectors a slightly smaller cam, and the twins have ceramic rear wheels in them but larger shafts, and a few other very small differences No EGR valves, but have map sensors.

GL.

TweakTech

iTrader: (2)

OK, I will sum this up. If you want a GTE swap into your OBD-II SC, and still retain all of your OBD-II functions, and pass emissions, yes, it's possible. I've even done a harness to convert a JDM Aristo 2JZ harness to work with a USDM spec OBD-II ECU into a TACOMA! It's more than possible!

Ali SC3

iTrader: (10)

I just assumed you had a vvti motor, you can do it without, you will need an odb2 ecu that is non vvti.
also you will have to add all the ignition stuff then if you are starting with a non-vvti odb2 harness.

Also as other stated there are EGR differences between the 2 when dealing with non-vvti.
Vvti does not have egr on both engines USDM or JDM which would make it more of a straight swap.

and all VVTI's had maf's. doean't matter if it was USDM or JDM.
only the non-vvti JDM ecu's used a map sensor for fueling.

Tweak is definitely right and a valuable source of information. if you know what you are doing you can wire most toyota's together.
Oh and my car drives great on the aristo ecu. I may get a manual supra ecu to see if there is a difference seeing as I am 5 spd, but it starts, idles, and drives like stock again, and thats impressive for my FFIM, q45 throttle body, and rigged up IACV on a 9:1 compression na-t setup.

grumpi300

iTrader: (1)

no i dont have anything yet. i just wanted all this information so i can know which to save up for, obd1 sc300 or obd2 sc300.

so thanks to everybody for such useful and insightful information. i now know which to get. ***obd2***

buying a 97 sc tho is gonna be the easy part. saving up for 97 usdm 2jz-gte, 97 usdm supra ecu, a 97 usdm supra wiring harness, and a r154 transmission is also easy. the hardest part is obviously gonna be putting it in my sc. and hoping i do it all right to be able to pass smog.
ali, what did you mean by, "i have to add all the ignition stuff"?
i'm new to wiring and by no means am i in a rush to find out because itll take a long time before i actually get this project started. but knowing some stuff in advance would be a big help.

stockhatch

iTrader: (12)

If you don't own the car yet, do yourself a huge favor and buy an OBDI chassis. It will make swapping anything in much, much simpler AND cheaper.

grumpi300

iTrader: (1)

how so? is it easier to swap everything out. i mean im basically gonna just look for a shell. or a broken down lexus as long as it has a clean title. i dont care if it doesnt have a motor or anything.

stockhatch

iTrader: (12)

What I mean is, if you get an OBDI chassis, it opens up your ecu and engine choices to pretty much any usdm OR jdm engine. You won't have to jump through any hoops to keep the CEL off and pass emissions due to a finnicky OBDII setup.