My 1990 Celica GT Four (RC Conversion)

Redswan

New member
Mr Alltrac":16q2ygsc said:
How do you plan on bolting on the front calipers?

Without having them here yet. I read that the bolt holes for the front are in the same position for both. I think I just have to run a bolt with a nut on one side to hold it on. I also have to split them open to run this bolt apparently.
 

CMS-GT4

Active member
Since your good at drilling you can get around needing to split your calipers. You make a bar that goes behind the ears and drill then thread them.
 

Redswan

New member
CMS-GT4":2vt6nz36 said:
Since your good at drilling you can get around needing to split your calipers. You make a bar that goes behind the ears and drill then thread them.

So, to get around this I just held the nut with a wrench from behind and put the both through.

I'm having trouble with stabilizing the hub because it is 60.1 from the 54.1 so it oscillates. I ordered some bore rings that should stabilize this.
 

Redswan

New member
So a few pics of the progress on the front. I used IS300 rotors in the front that were redrilled by hand to 5x100. I have ordered 54.1mm to 60.1mm hub bore rings to fill the difference in the hub bore of the rotors. So, I will let you know how that goes.

ST185 vs ST205 front rotors (278mm vs 290mm

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IS300 Rotors mounted:
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IS300 rotors and ST205 front calipers together:
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For the Rear I am still waiting for the rotors to come in from the UK this week. I picked up a pair for $200 and they are supposed to be bolt on minus a small 54.1mm to like 55mm rotor center bore difference. So 'm looking forward to this conversion.
 

Redswan

New member
the brakes are probably my last project before i deploy again this summer. i'm going to start collecting parts for a ST205 ECU conversion. I have been reading up on it and heard pros and cons for it. I figure it is maybe worth a shot.
 

Redswan

New member
So, I got the rear rotors in the mail today. Everything mounted up great and quickly.


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ST185 vs ST205 rear rotors

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Redswan

New member
So, some feedback on the 205 brake swap. First off. No matter what you do, don't try to put the 205 front calipers on the 185 rotors. yes it will bolt up, but it will ruin your pads, plus it isn't safe.

Second, it seems to me that the ABS makes it a little mushy. I tested it out and it seems more responsive to 'unplug/turn off' the ABS I t might just be me though. Again not exactly safe, so I don't recommend doing this.

However, the setup seems to stop faster and it looks coool that the brakes say 'CELICA' on them :p
 

Redswan

New member
Ok, so next project. I'm looking to swap the 540cc (ST205) injectors and ECU. I know there are some limitations, but I also know it can be done. I'm weighing wether to use the OEM ST205 one or try to find a Apex'i power FC. If anyone has any feedback on this it is welcomed.
 

Corey

Active member
I did this conversion, except using an MR2 ECU since I don't have a WTA intercooler and didn't want the error codes.

Best mod I've ever done. I've yet to see any limitations, even using the 185 turbo. Ideally the 205 or similar turbo would be used.

Brian from Berk Technologies made a jumperharness specific to my application (1989 ST185 to GenIII MR2) and it works perfectly. I'm using ST205 injectors, MAP, temp sensors, and Ignitor.

The 2 temp sensors were wired up to the pins on the now disused AFM harness in the engine bay. These wires were then repinned using the jumper harness to match the temp sensor pins of the MR2 ECU.

The MAT took the place of the cold start injector and the IAT sensor just sits in my new straight intake.

I deleted the TVIS by installing the KO racing delete plate.

The 205 ignitor plug had some extra bits that needed to be filed down to fit inside the 185 female plug.

https://www.berktechnology.com/store/st ... ectronics/
 

Redswan

New member
Corey Darling":35z3y732 said:
I did this conversion, except using an MR2 ECU since I don't have a WTA intercooler and didn't want the error codes.

Best mod I've ever done. I've yet to see any limitations, even using the 185 turbo. Ideally the 205 or similar turbo would be used.

Brian from Berk Technologies made a jumperharness specific to my application (1989 ST185 to GenIII MR2) and it works perfectly. I'm using ST205 injectors, MAP, temp sensors, and Ignitor.

The 2 temp sensors were wired up to the pins on the now disused AFM harness in the engine bay. These wires were then repinned using the jumper harness to match the temp sensor pins of the MR2 ECU.

The MAT took the place of the cold start injector and the IAT sensor just sits in my new straight intake.

I deleted the TVIS by installing the KO racing delete plate.

The 205 ignitor plug had some extra bits that needed to be filed down to fit inside the 185 female plug.

https://www.berktechnology.com/store/st ... ectronics/





Thanks for the feedack. Was there any other wiring changes or re-pinning for the mr2 ecu versus the st205 one?
 

Corey

Active member
The only differences would pertain to the WTA setup. If your car doesn't have the original WTA wiring then there will be nothing to supply to the 205 ecu to make it happy. If I recall, this results in engine codes and limp mode.

EDIT: I just reviewed the Celicatech thread and they discuss the issues encountered with the 205 ECU and how to fix them. Personally, I'd just run the MR2 ecu, they are easier to find anyways.
 

Redswan

New member
Corey Darling":14fblc1u said:
The only differences would pertain to the WTA setup. If your car doesn't have the original WTA wiring then there will be nothing to supply to the 205 ecu to make it happy. If I recall, this results in engine codes and limp mode.

EDIT: I just reviewed the Celicatech thread and they discuss the issues encountered with the 205 ECU and how to fix them. Personally, I'd just run the MR2 ecu, they are easier to find anyways.


Thanks, yeah I read the celicatech article too, I was concerned about using the MR2 Rev3 because the 22 pin (body) on the right doesn't match the celica. I didn't know if they were compatible without rewiring or repinning the ECU. I bought the jumper harness so that i can plug in the 205 ECU. I'm trying to source a 205 MAP sensor for cheaper than $170.

So with that said is the REV3 MR2 ecu part number 89661-17460?
 

Corey

Active member
Yep, that's the part number for the JDM ECU, which I'm running.

The USDM part number is 89661-17470
 

Redswan

New member
So,

I bought the ST205 ECU since I have a WTA setup and level sensor in the IC already, we will see if this works.

So for parts going into this thing
ST205 ECU: 89661-2B840
ST205 MAP Sensor: 89420-17050
ST205 Ignitor: 89621-16020
Air intake sensor
MR2 Rev3 540cc Injectors
I also picked up a jumper harness from Ripley/Keri

So coming into this I think i have a pretty good grasp on what I need to do, but time will tell.
 

nickfootball

New member
Redswan":xm4q8ioe said:
Also for this RC Badge remake...I need to know how much demand there is for them before I make a run at it.
Hi Mike,
I'd take 2 RC badges if you do manage to make them. I also think you would get a good demand for them. I can ask on the gt4oc site to find numbers interested?
Well done on the purchase of the RC number plaque, what a find! I have been looking a few years too but not as long as 15 years so you well deserve it :) can I ask how much it cost? I have seen one previously before but that was going for approx $1000!
I will finally take one of your replica plaques if you still have them, I have your details via IM.
Your project is looking brilliant and I look forward to more updates on it.

Nick
 
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