HiPSI

iTrader: (2)

Can we get an official Ali write up on this conversion .

I thought about this option in the very beginning but figured it would be alot more complicated then just sticking NA-T.

The idea of it having all the available head aftermarket upgrades, endless turbo manifolds, cam options, factory forward facing intake manifold would make it an ideal swap.

Ali SC3

iTrader: (10)

Kahn is about to or doing this right now. keep an eye for his build thread, its going to be a na-t with a gte head built to be like a gte basically.

Its really not much different than re-installing your GE head after you replace the headgasket you should be generally doing anyways when you go na-t. the GTE head will bolt on to the block and all the intake and exhaust stuff will bolt on to the GTE head. may be a few coolant hoses to work out but run it like all like a gte basically and if you are single turbo you can bypass some of that stuff.

for wiring some plugs will have to be moved around or extended to reach their new places if using a GE harness.
I would keep the GE harness if going single, but if going twin turbo and you want to keep sequential it may be better to get a swap harness that will be plug and play for the twins and everything. If you are auto the plugs on the gte auto harness might be different just transmission wise (consider then running a gte auto in that case).
So when using GE harness the intake stuff can generally unwrap the GE harness some and just pull back those wires to the GTE FFIM spots like tps, IACV, etc... ones that will need extending are the crank sensor from the distributor spot down to the oil pump (IF you are 96+ you already have this wiring in addition to your distributor wiring, just have to move a pin at ecu; 92-95 you just extend the distributor wire down some with shielded wire).
For the 2 cam sensors on the gte head, you peel back the 2 distributor cam trigger wires, and then you run the previous shared ground (for distributor) to all 3 new grounds, 2 for the cam sensors, and 1 for the crank.

last item that needs to be done for this mod is the crank sensor and crank gear. if you are 96+ you already have an oil pump mounted crank sensor as 96+ has a 2nd crank senesor just like a TT crank sensor. only difference is that the gear the sensor reads is not a 12-1 trigger wheel its like a 36-2 or something like that I forget. basically you have to remove the crank pulley and change out that one trigger wheel for the gte one.
If you are 92-95 you do not have the right oil pump for this, and must install a 96+ 2JZGE oil pump with the TT crank gear. this generally requires pulling the motor, which is why I said if you are 96+ that is lucky if you want to put on a gte head as you can change out the trigger wheel much much much easier than the oil pump.

Avoid using a gte pump when using a ge block, use the 96+ge oil pump for mounting the crank sensor and not the gte oil pump. The gte pump is designed to flow extra oil for the squirters and using it on a GE block will cause high oil pressure, blowby issues and main seal issues.

Kris9884

iTrader: (7)

^^^ That all sounds like a ton of work but not really if you have everything you need, maybe a weekend. Totally worth the results of cams, manifolds etc as stated before.. Interesting info.

Ali SC3

iTrader: (10)

Well these days with a nice FFIM you can avoid all of that, and you can always use GTE intake cams on a GE motor. for the exhaust cam there are actually a few available now and alot of custom grinds the only difference is that the GE exhaust cam has the ring on it for the distributor gear, otherwise physically the cams are eerily similar. This is why some people have just used the GE head and welded 2 crank sensors on it, and then drop in gte cams and the oil pump as I said above, and then you get a full distributor delete on a GE head. coupled with a good FFIM and GTE valve covers, its looks pretty mean like a gte except the water neck is on the correct side being a GE head, not that its a big deal though.

all the ways are good ways but some require alot more work than others. I rather order custom cams and intake then bother with pulling the motor to change an oil pump and change out the head. only real advantage is that for stock twin turbo's you pretty much need the gte head, but single turbo.. works just the same on a ge head and manifolds are readily available.

I just got my 4" pipe in that I am going to make an intake manifold out of with the GE upper runners I cut, now to start figuring out how to make the 2 parts into 1 without ruining both of them in the process. will post pics if I make any progress.

BuffNStuff

Is anyone else having headlight issues? I still haven't figured out how to get my headlights to work. I can't find the wiring diagrams I need. Do supras have automatic headlights?

Also thinking about upgrading to a tt auto. So I'm gonna hold off on messing with my transmission wiring until I know how to do the swap.

BuffNStuff

Does anyone have any links to the transmission pinouts for the 1997 sc300 and Supra TT? I cant find them anywhere. I have no idea how to wire either the stock tranny or the tt auto up to the TT ecu.

In the post ALI made, it mentioned that the relay for the lock up solenoid was for obd1 cars. I also have 2 other shift solenoid codes that I would either have to fix, or rewire if I use a tt auto.

Ali SC3

iTrader: (10)

shouldn't be having headlight issues really I don't think that is related. haven;t had any issues with mine they are automatic and still working the same but I guess I am obd1.

Upgrading to a TT auto is likely a good idea if you want to stay auto. either that or go manual and use a manual ecu to get rid of all the codes. really the stock GE auto is not going to last that long anyways unless you can live under 350rwhp and even then its risky.

I think I posted some many pages back, but not specific to the 97. Just the GE and the GTE versions. your trans is the same kind on the obd1 versions I don't think there is much difference wiring or trans wise.

you probably have codes for the lock up one, the shift line pressure solenoid, and I can't think of the other one.

Everything needed for the stock tranny with the exception of the lock up is already wired up, the rest of the stuff isn;t used by it and would only be used by a gte auto. so you can either trick those relays/solenoids/vsv's somehow or go GTE auto and wire it all up (basically part of what tweak on a harness, we would have to figure it out I think Gerrbs thread has alot of info in it about this stuff), or last option is manual swap and use a manual ecu and don't worry about any trans codes or use the auto ecu and trick bypass the ecu.

If you won't fail for trans codes I wouldn't worry about fixing those just the lock up function, but it seems the relay didn't work for some reason will have to look into it again.

I know the v8 guys get rid of the codes by just connecting the solenoids and tying them out of the way somewhere under the car, so that would involve getting GTE solenoids, but maybe there is an easier way.

I am not really an auto trans guy, so yeah you guys might have to work on that front. have to see if I can find any of the 97 diagrams.

Kris9884

iTrader: (7)

Are you running aftermarket ballasts? I assume they worked before the swap/wiring issue yeah? Yes, the Supra does have the auto off lights like ours, once the door opens, they turn off.

BuffNStuff

I haven't modified my headlights, and they worked fine before this mod. Do the wires for the headlights run through the driver side wheel well? I am wondering if maybe they got chewed by my tires...even though I tucked them up and away. Hmmm. Looks like I'll have to break out the multimeter again.

There aren't any wiring differences between the manual tt ecu and the auto tt ecu right? So theoretically, I could do a manual swap and not have to change any of the wiring?

Kris9884

iTrader: (7)

I wish I could give you an accurate answer to that. I know you can run the auto ECU with a manual setup and wont notice anything but I don't know the other way around as it may have shift points and for certain things in the car to work if you are only in park etc... If I remember correctly the TT transmission had a separate computer it ran off of but I may be wrong.

Ali SC3

iTrader: (10)

There is 0 wiring difference between a TT manual ecu and auto ecu. On the manual ecu, the pins for the auto stuff are simply not functional, and will not display auto codes.
If you did a manual swap and swapped out the ecu's, you would need to connect the reverse light switch and the speed sensor on the transmission. that would be it as far as I know.
You should be able to wire that up to your existing auto plug that's there, or modify the plugs to the manual plugs mentioned above, or you can start over with a manual harness but its like 5 wires I think so I wouldn't do that.

I think its more likely that the wires did get chewed for the lights int he wheel well. did you have damage there before?
see post 8
https://www.clublexus.com/forums/sc-...t-turn-on.html

you can't run an automatic trans with a manual ecu, but the wiring harness for everything but the trans is the same. The gte's auto control is built into the ecu. some lexus's have the seperate auto ecu but not the case with our cars or gte's.

myLEXsc400

so the shop that i took my car back to so that they can fix my TPS issue claims that they cannot set the timing in my car because i don't have an active distributor because i have ignotion coils, so that eliminates it from the equation, so they cant set the timing or sync it. How do i properly explain to them what to do?

BuffNStuff

Yes they can. You SHOULD still have the distributor there, but with no spark plug wires on it. If your tps is out of adjustment, you will not be able to set the base timing. There is a sensor in the distributor that is still being used by the ecu. To change the timing, you only have to loosen the nut that holds the distributor in place and rotate the whole distributor clockwise or counter clockwise depending on what your timing is at.

Put the transmission in neutral, hook up a timing light, start the car and put a jumper in between terminals T1 and TE1 in the little black box that sits on the front of your engine on the drivers side. Pop the cap off and put the jumper in. When you do this, you should hear a change in the engine rpm. If you don't hear a change, your tps is out of adjustment, and you can't set the timing. The timing should be set between 8 and 10 degrees before top dead center. This should put your distributer rotated almost all the way clockwise (you can only rotate it so far before you can't physically rotate it any further) With the jumper in, the engine running, and transmission in neutral, hook up the timing light to the number 1 spark plug wire. It is just a clamp that you put anywhere on that wire. The light on the end of the timing light will start to flash. It flashes everytime a currant pulses through the spark plug wire. Point the light at the top of the crank pully on the drivers side. You will see numbers on the pully with a small arrow, and a white line on the serpentine belt. When you rotate the distributor, the white line will move in relation to the arrow on the crank pully. You want this line to be where the number 10 arrow is or maybe a tiny bit to the right of it where 8 degrees BTDC would be. When you get the line slightly to the right of the number 10, tighten down the nut for the distributer (be careful not to accidently move the distributor while doing so) and take out the jumper for the 2 pins in the black box (it's called the diagnostics block) and disconnect the timing light.

It's all really simple after you get the hang of it. It took me 20 minutes to do my first time and that was only because my tps was out of adjustment and you CANT set the timing if it is. After I got my tps sorted it took 5 minutes to set the timing.

I bought my timing light off amazon for $30. You just need a basic inductive timing light. Not the fancy digital one.

myLEXsc400

Thank you very much for the quick response. Life saver. I appreciate it.

Ali SC3

iTrader: (10)

what buff said is exactly correct. when the tps is in the right spot at idle all toyota ecu's will let you go into a sort of test mode where you can set the timing, or at the very least verify it even on a gte motor where you can't change is sometimes they check it for emissions and that is how you do it. so you put it in that mode but the tps has to be in the right spot or it wont let you in, you can tell by the change in sound. because we have a distributor we can change the base timing like on a ge, and all the ecu's work the same way. that could explain alot of issues if the timing is off so be sure to do that next.