1g N/A Auto to T Manual swap

[SigSauer]

Hello everyone, first time posting a thread here.

I picked up a 90 GST 5spd with a clapped out body and a 91 GS auto in near mint condition. I am going to swap the trans, turbo and all supporting components from the 90 to the 91.

What should I be pulling from the 90 besides the obvious?

I would like to use the turbo cluster, but will I need to transfer harnesses?
How about the ecus?

I hope I get some solid feedback on this so I can start gathering additional parts if I need them. I was hoping that just having an entire parts car would take care of that but it looks like there were some under the skin differences between 90 and 91.

Thank you all in advance.

 

[motomattx]

You would want the harness and the ecu if you want to make it simple, the 90' stuff has different plugs on most of the sensors and ignition coil and power transistor, so I recommend that you pull it ALL and swap it over.

 

[19Eclipse90]

Seconded. There's going to be a lot of differences, not only because it's a 1990 and a 1991, but also due to the 1990 being a manual and the 1991 being an automatic and the fact you want to keep it manual. You are correct to a point, at least. Between the two cars, you should have everything you need to complete the swap.

- Brake and clutch pedal assembly
- Gear selector and linkages
- ECU and ECU harness
- Because you want the turbo cluster, cluster and dash harness (this requires removing the dash)
- Clutch master cylinder and line to slave cylinder
- All motor mount sets
- Axles
- Cruise control (if so equipped and desired) with all associated components and mounting brackets
- Intercooler with piping and ducting
- the 1990 should have an external oil cooler in front of the A/C condenser, mounting for which would need to be swapped over if you wanted to retain that.
- fuel pump, fuel rail, and fuel pressure regulator

Even that may not be taking everything that's not so obvious (engine and transmission, duh) into account. It's a pretty involved process but it's definitely doable if you pay attention to the details. We're here to help if you stumble across something that doesn't make sense.

 

[pauleyman]

Seconded. There's going to be a lot of differences, not only because it's a 1990 and a 1991, but also due to the 1990 being a manual and the 1991 being an automatic and the fact you want to keep it manual. You are correct to a point, at least. Between the two cars, you should have everything you need to complete the swap.

- Brake and clutch pedal assembly
- Gear selector and linkages
- ECU and ECU harness
- Because you want the turbo cluster, cluster and dash harness (this requires removing the dash)
- Clutch master cylinder and line to slave cylinder
- All motor mount sets
- Axles
- Cruise control (if so equipped and desired) with all associated components and mounting brackets
- Intercooler with piping and ducting
- the 1990 should have an external oil cooler in front of the A/C condenser, mounting for which would need to be swapped over if you wanted to retain that.
- fuel pump, fuel rail, and fuel pressure regulator

Even that may not be taking everything that's not so obvious (engine and transmission, duh) into account. It's a pretty involved process but it's definitely doable if you pay attention to the
details. We're here to help if you stumble across something that doesn't make sense.

I realize the 91 is non turbo but wouldn't it be easier to leave the 91 harness in place? Op would already have coil, tps, cas in place. Need to add knock sensor circuit. What else? Easier to swap sensors than a whole harness.

 

[19Eclipse90]

OP wants to use the gauge cluster from the 1990. We know that tach doesn't work with 1991+ electronics. Boost gauge won't work without swapping dash harnesses or adding wiring. No point in swapping clusters if the functionality of the boost gauge isn't desired.

Also MAF idle reset, boost control solenoid, other turbo-related solenoids if desired. Then sorting through all the auto stuff that won't be needed.

There's plenty of ways to go about it. Really depends on what the OP wants to do and going off what they posted, that's what it will take.

 

[92AWDHX40]

This was a interestng a auto swap to manual swap i did a few years back, quite a few things to change out. Learned a lot though.

 

[SigSauer]

I appreciate all the feedback guys. This is great info. I want to use the 90 (boost) cluster for originality but if its going to really add a boat load more work...maybe i should keep the 91 cluster in place. Actually, is it even possible to swap odometers? If not then nevermind it swapping clusters.