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I figured since no one reads the 1JZ swap sticky thread, if I wanted answers I'd have to risk pissing someone off and starting a new thread :p

Just to clarify: the 1JZ R154 bellhousing is needed to bolt up to the 1JZ-GTE, but instead of buying the whole tranny, I can swap in the guts of the MA71 7M-GTE R154? Where would I get this done? This just accomplishes using the right bellhousing to bolt up to the 1JZ, while having a 1JZ input and 7M output so the original 7M driveshaft would fit?

The swap seems more straightforward than I thought - pull the 7M, drop the 1JZ in, bolt up the tranny (MA71 R154 guts in the JZA70 R154 bellhousing), and install the harness and ECU. Once I get the harness and ECU in, the rest of the problems should be relatively minor, correct? (i.e. plumbing and piping, physically fitting everything)? It doesn't seem much harder than a 7M-GE to 7M-GTE swap, except for the harness differences. Am I missing something? It always sounded like a bigger project than it seems now.

Has anyone used the STOCK twins from a 1JZ and still been able to use the A/C?

I need to make a hybrid harness by (in addition to lengthening it) combining the 1JZ-GTE and 7M (GE or GTE) harnesses, but what do I need to keep from the 7M harness? Dash connections, I assume? Or, if it's a shorter answer, what do I need from the 1JZ harness? If I'm splicing in (for example) the tach connection on the dash, do I just cut that connector from the 7M harness and splice it into the tach sensor line from the 1JZ sensor, basically just changing the end of the dash connection to something that would fit the 7M dash?

Sorry for the probably repetitive questions, but there was a lot of conflicting and unclear information in the 1JZ sticky. www.supras.nl helped me out a bit, but I'm trying to clarify the questions, and posting in the 1JZ thread probably won't get me an answer. Sorry if this is a pain in the ass (mods), just give me a few days, I'll delete it as soon as I get an answer. Hopefully this won't become the same conflicting thread as the sticky.

TIA guys.
 

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Well. for the most part, you're on. The R154 bell housing is the only thing you need for the transmission. Also, the flywheel is different than the 7M's.


It gets more complicated the more things you change. I went from an NA automatic, w/ABS and a security system to a TT 5-spd w/ no ABS or security. The wiring for the security system is not in the harness and will need to be added. The ABS sensor for the manual was not there either. I needed one for the manual transmission, the wiring was in the harness. I went aftermarket for turbo boost to avoid that whole mess with the computer and wiring to support the gauge. May do the same for the security system.

Always, there is the crossmember issue for cars with a mfg date before 8/88.

Power steering hose is from the 2JZ and bolt.

Also, no oil pressure gauge hookup. I recommend getting a reloc kit with ports and pulling the oil pressure from that.

AC system is still and open question for me. However, I suspect I will have a custom hose made to complete the system. Not sure which hose yet, but that seems to be the solution.

Buy a engine seal kit and timing belt from Jeff Watson @Champion Toyota in Texas. The kit has every seal in the motor for $145. Well worth the expense. The belt is the Toyota 1JZ belt and is less than $21.

Use USB cable for the shielded wires (there are 7 of them, 2 KS, Crank, 2 O2, 2 Cam) and make sure to get the shielding right or pay HamsMkIII or someone else on the board to do the harness for you. You may want to have Hams do your body connectors, he does a great job.


Just look at those basic things before you get started. Size it up and go. There is definitely more expense than I first thought as well as work. However, I am anal about doing things a certain way.

Good luck,
Marty
 

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Discussion Starter #3
Yeah...I was planning on getting a lightweight flywheel anyway unless I can find a 1JZ one for cheap. Same with the security - if I put all this time and money into it, it will get a top-of-the-line alarm, probably a Viper.

The body would be 89+, probably 90-91 if I have my way.

By oil reloc kit, you mean the oil filter relocation? And tap into the lines running to the filter for an oil pressure?

I was thinking the same thing as your custom AC...is it the condenser that's in the way of the second turbo? Let me know what you end up doing, I would like to have AC if possible, I can't stand 95 degree days, but my old Supra's AC was dead, so I guess I could live with it.

Me and you are a lot alike :) - if I decide to do it, I'm doing it right the first time. I'd rather spend more money the first time around and avoid wiring problems and reliability issues. If something's too much of a PITA, it's getting replaced by something aftermarket if that's an easier solution.

That's all good news - physically dropping the motor in isn't a problem, the tranny won't be a problem (JARCO has a JZA70 front cut with the complete R154 for $2995, it's out of stock though :(), the harness would be the only issue. People have swapped the 1JZ gauges (speedo or tach, I forget which one), and it's apparently a direct fit - that would be one less thing to rewire as well, as the 1JZ connector would plug right in.

So basically, it's a complete swap just like anything else, and the dash gets wired up to display the outputs from the 1JZ, and it works fine. I love Toyota :). Any major issues besides the harness I should be aware of? This is good news...I've been Supra-less since October 2004, and without a running Supra since May 2004, and somehow my Explorer doesn't quite cut it :(

Thanks Marty :D
 
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Marty1MC said:


Use USB cable for the shielded wires (there are 7 of them, 2 KS, Crank, 2 O2, 2 Cam) and make sure to get the shielding right or pay HamsMkIII or someone else on the board to do the harness for you. You may want to have Hams do your body connectors, he does a great job.

what do you mean by body connectors, the connectors between the engine harness and the dash harness? or other ones?
 

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Tska,your not actually running wires to the dash gauges.your just rewiring a couple of plugs from the 7m harness onto the 1jz.
 

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tsuper92 said:
Tska,your not actually running wires to the dash gauges.your just rewiring a couple of plugs from the 7m harness onto the 1jz.
Correct, NeverNZ, that is what I meant by body connectors. HamsMkIII has what I think is the best solution and the one I am going with. Create connectors that bridge the 1JZ to the 7M. Real sweet solution and has the advantage of allowing troubleshooting simply by pulling out the jumper connectors. I have a picture of them that he sent me.

The engine bay wiring is not really documented anywhere. But I was able to move over the EA2 connector with 3 wires spliced. Two were for the alternator lights and one for the AC compressor clutch. I even was able to move over the the battery wiring including the connection to the main fuse box. I did this because the clip had a very good condition harness and mine was not. My fusible link from the battery was toast and kept disconnecting during driving.

The alternator extension is pretty straightforward as well. Just get some 4 or 8 gauge cable and a couple of splice blocks from home depot (2 orf them were under $5. ) This allowed me to splice the original connector to the alternator and the wire into the fuse box as well as the wire that goes to the fusebox inside the cabin without any problems.


Also, I believe that all you need is the bellhousing to mate your R154 to the 1JZ. (not easy to find and expensive when you do, like $400) The body of the transmission is the same. Also, the flywheel is different as well. I think it is a 7M flywheel with 2JZ bolt holes.

But generally agreed. It isn't as bad a swap as first thought. I made a list of "to do's", parts and research items. As I finished them I crossed them off and added to it along the way.

Good luck...

Marty
 

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Discussion Starter #7
Marty1MC said:
Correct, NeverNZ, that is what I meant by body connectors. HamsMkIII has what I think is the best solution and the one I am going with. Create connectors that bridge the 1JZ to the 7M. Real sweet solution and has the advantage of allowing troubleshooting simply by pulling out the jumper connectors. I have a picture of them that he sent me.


Also, I believe that all you need is the bellhousing to mate your R154 to the 1JZ. (not easy to find and expensive when you do, like $400) The body of the transmission is the same. Also, the flywheel is different as well. I think it is a 7M flywheel with 2JZ bolt holes.

Could you post a pic of the connectors? Is it basically like a smaller harness so the original 1JZ harness doesn't need to be modified (except lengthened)? 7m plugs on one end, 1JZ on the other, and it plugs in between the 1JZ harness and whatever 7m part is on the other end, i.e. dash. Is that what you're getting at?

JARCO actually has a front cut JZA70 that comes with the complete R154 tranny, total of $500 more than the auto tranny, and no need to swap anything into the JZA70 bellhousing, so as soon as they get one in stock I'll pick it up from there. The flywheel is a 1JZ-GTE compatible flywheel and clutch, as the input end of the tranny is 1JZ. Will a JZA70 R154 be compatible with the MA70/71 driveshaft?

Thanks for the help guys.
 

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Actually, the picture in the thread I posted is the picture you are looking for. It show connectors from a 1987 mated to the 1JZ body connectors. If you have a 89 and above you will have grey and white connectors instead of the two yellow ones. And yes, these are the dash connectors. You cut off the connectors inside the dash of the 1JZ (not any from the harness for the engine, just the ones on the inside of the dash for the clip, non-ecu.) and you cut off the connectors from the engine wiring harness on the 7M, again non-ECU. These will make an adapter harness.

Marty
 
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