The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support ExtremePSI
Please Support STM Tuned

Picked up a mid-swap project

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Larry33

Probationary Member
10
2
Jan 14, 2021
Plattsmouth, Nebraska
A bit of a newbie thread, but I've done a ton of research and reading of these and other forums. I recently picked up a 97 GST Spyder Manual Transmission, and it looks like they were in the middle of a 6 bolt swap and 16G turbo upgrade. I validated that the block came from a 91 Turbo FWD, transmission is a F5M33 (not sure how to tell if it's the 91's tranny or not).

Issues:
- I have no idea what the state of the motor/tranny is. I'm going to take them both out and go through them looking for any damage or worn parts.
- Wiring is a mess, they cut a bunch of stuff off. I'll go through the whole harness when the engine comes out.
- Convertible top is broke, a lift arm snapped in half.
- This thing sat outside for a long time. Interior is wet and moldy, even had a mouse living in the trunk.

I have a donor car, a 1999 GS Spyder Auto Transmission with a blown head gasket. I'm going to fix the head gasket, and then take the motor/tranny out and sell it locally. I'm going to steal the entire interior, the whole convertible top, wheels, a couple body panels, and a few odds and ends like windshield washer tank and coolant overflow tank. All other parts will be listed in DSM classifieds. Then she goes to the scrapyard.

Questions:
- What else can I steal from the 99? I take it the wiring harness would be too different from AT to MT to make it worthwhile?
- Can the ECU be swapped if my 97's is bad?
- Is there anything else I should be aware of? (Common issues or mistakes the previous owner might have made in attempting the 16g/6 bolt swap)
- When I get the tranny off, what do I need to look for to make sure the tranny is correct for the motor? (other than seeing that there are 6 bolts on the flywheel)

Thanks for any feedback, these forums have been super helpful already. Looking forward to the end results of this long project.
 

Attachments

  • PXL_20210119_172252620.jpg
    PXL_20210119_172252620.jpg
    1.3 MB · Views: 40
NT ecu is not correct for a 4g63 turbo car. Wiring harness is differnt also but you could use pieces of it/add to it etc.
You can take any and all body and interior parts. Never know what you might need.
Tranny can't be from the 91. It does not have provisions for the mounts. Likely it still has the original 97 trans.
Trans is not 6bolt. If it's an f5m33 and it's bolted in at this point you can assume it's a 2g trans (it would have to be) and nothing else needs to be done. All turbo clutches 90-99 are the same you just have to pair it to the correct stepped flywheel for whatever car you have. 4 options. 6 bolt FWD and AWD. 7 bolt FWD and AWD. Thats it as far as flywheel.
 
Since both cars require a lot of disassembly, I'm wondering if it might be easier/more worth it to swap your 4G63 into the 99 instead of swapping the interior and top into the 97. Depending on what the chassis is like on the 99, of course.

I've only ever driven one 2g/6 bolt and the swap was so bad that I reverted it back to 7 bolt after less than two months of owning it. The dealbreaker issue had something to do with adapting the 1g CAS to a 1995 wiring harness (cam sensor in cam gears) that caused a fantastic electrical resonance or interference that would cause it to drop two cylinders between 65 and 75 mph. I wouldn't think that would be a problem here since the 97 used a CAS on the intake cam like the 1gs. In general I'm pretty negative toward 6 bolt swaps since the 7 bolt head is a big improvement and across the 6x 7 bolts that I've owned I've never experienced a bottom end failure beyond a lack of oil due to owner negligence.

But enough of my soapbox. Beyond the CAS wiring, I would just keep an eye out for signs of half-assery, which is a pretty big challenge when the swap is MAYBE half complete like it is here.
 
I would agree on motor swap except that one car is auto and the other is manual. That adds a lot of issues. Interior swap is very very easy by comparison.
 
You didn’t mention any rust, so assuming there isn’t any on either car. 2G seem to be far more prone to that compared to 1G (which is kind of weird, but seems to be the trend). Just the wet moldy description made me wonder.
I agree that the interiors are like an oversized lego set, at least on my 1G, and assume they used basically similar construction on 2G.
Post a few photos for the before/ after effects.
 
Tranny can't be from the 91. It does not have provisions for the mounts. Likely it still has the original 97 trans.
Trans is not 6bolt. If it's an f5m33 and it's bolted in at this point you can assume it's a 2g trans (it would have to be) and nothing else needs to be done. All turbo clutches 90-99 are the same you just have to pair it to the correct stepped flywheel for whatever car you have. 4 options. 6 bolt FWD and AWD. 7 bolt FWD and AWD. Thats it as far as flywheel.

What do you mean "provisions for the mount"? Does that mean the 1G trans can't natively mount to the 2G engine bay? And if it is a 97 trans mounted to a 1G motor, is the 97 flywheel correct, or do I assume that they brought the 6 bolt flywheel over from the 91? I thought I had read that the teeth count was different, or does that only matter for AWD trannys?
 
Last edited:
Since both cars require a lot of disassembly, I'm wondering if it might be easier/more worth it to swap your 4G63 into the 99 instead of swapping the interior and top into the 97. Depending on what the chassis is like on the 99, of course.

I've only ever driven one 2g/6 bolt and the swap was so bad that I reverted it back to 7 bolt after less than two months of owning it. The dealbreaker issue had something to do with adapting the 1g CAS to a 1995 wiring harness (cam sensor in cam gears) that caused a fantastic electrical resonance or interference that would cause it to drop two cylinders between 65 and 75 mph. I wouldn't think that would be a problem here since the 97 used a CAS on the intake cam like the 1gs. In general I'm pretty negative toward 6 bolt swaps since the 7 bolt head is a big improvement and across the 6x 7 bolts that I've owned I've never experienced a bottom end failure beyond a lack of oil due to owner negligence.

But enough of my soapbox. Beyond the CAS wiring, I would just keep an eye out for signs of half-assery, which is a pretty big challenge when the swap is MAYBE half complete like it is here.

With the 99 being an Auto and the 97 a Manual, I'm going to keep the 97 shell. It's actually very rust-free, considering how wet the inside was. I'm guessing it got moved from a garage to outside recently and got rained on and leaked in from the convertible top.

I've seen the stuff about making the CAS work, and I think there's enough write-ups out there that I should be able to take care of that part. If I run across a great 7 bolt engine locally I might consider the swap, but for now I'll just hope that I can avoid crankwalk with this 6 bolt.

And there is plenty of half-assery in the wiring department. Took the dash off today, they just cut the wire off for the factory boost gauge and ran different wires to relocate an aftermarket gauge to the pillar. I've also seen lots of hoses in the engine bay capped off for no apparent reason... It's gonna be a long teardown and rebuild, LOL.
 
You didn’t mention any rust, so assuming there isn’t any on either car. 2G seem to be far more prone to that compared to 1G (which is kind of weird, but seems to be the trend). Just the wet moldy description made me wonder.
I agree that the interiors are like an oversized lego set, at least on my 1G, and assume they used basically similar construction on 2G.
Post a few photos for the before/ after effects.

The 99 actually has a bit of rust, and some minor JB weld on the strut towers and a couple other places. 97 is pretty clean. We're going through the floorpan right now buffing off surface rust and then we'll cover with a sealant before we swap the interiors.

We are keeping a good log of progress pictures, I even started an Instagram account for the car: https://www.instagram.com/charlottespyder/
 
What do you mean "provisions for the mount"? Does that mean the 1G trans can't natively mount to the 2G engine bay? And if it is a 97 trans mounted to a 1G motor, is the 97 flywheel correct, or do I assume that they brought the 6 bolt flywheel over from the 91? I thought I had read that the teeth count was different, or does that only matter for AWD trannys?
Correct, the 1g trans can't mount in a 2g.
Flywheel has to match both engine and trans. The flywheel isn't so much native to 1g,2g but rather 6 bolt or 7 bolt and awd or fwd. This makes 4 options available. I suppose you could say a 6bolt is 1g because only 1g came with 6 bolt but anyway....
So you have 6 bolt flywheels both awd and fwd and of course 7 bolt flywheels both awd and fwd. The 97 flywheel is not correct as that would be a 7bolt. They would've had to bring g a 90 to 92 6 bolt flywheel. As you are fwd yes it has to be a fwd flywheel and yes that is where tooth count matters.
 
Correct, the 1g trans can't mount in a 2g.
Flywheel has to match both engine and trans. The flywheel isn't so much native to 1g,2g but rather 6 bolt or 7 bolt and awd or fwd. This makes 4 options available. I suppose you could say a 6bolt is 1g because only 1g came with 6 bolt but anyway....
So you have 6 bolt flywheels both awd and fwd and of course 7 bolt flywheels both awd and fwd. The 97 flywheel is not correct as that would be a 7bolt. They would've had to bring g a 90 to 92 6 bolt flywheel. As you are fwd yes it has to be a fwd flywheel and yes that is where tooth count matters.

The motor came from a FWD 91 (based on VIN). If they left the original 97 tranny in there, and brought the flywheel over from the 91, it sounds like it will be correct. From what I've read, the AWD is a 106 tooth and the FWD is 110, so I assume the 6 or 7 bolt is all that matters. If I replace the flywheel, I assume I just look for a 6 bolt flywheel and all should be good.

Follow up question, other than the CAS issue, is there anything else in the wiring harness that won't match up correctly from a 2G harness to a 1G engine?

And thanks a bunch for the quick reply's and help on this, I know I'll have lots more questions once I tear the engine/tranny out and start breaking it down. :)
 
Tranny can't be from the 91. It does not have provisions for the mounts. Likely it still has the original 97 trans.
Trans is not 6bolt. If it's an f5m33 and it's bolted in at this point you can assume it's a 2g trans (it would have to be) and nothing else needs to be done.

Well, it is in fact a 91 tranny. Take a look at that rear roll stop...
So it looks like I'm going to be fabricating a rear roll stop for the 91 motor...
 

Attachments

  • PXL_20210123_014548594.jpg
    PXL_20210123_014548594.jpg
    1 MB · Views: 26
  • PXL_20210123_014701055.jpg
    PXL_20210123_014701055.jpg
    765.9 KB · Views: 29
  • PXL_20210123_014757963.jpg
    PXL_20210123_014757963.jpg
    1.3 MB · Views: 32
  • PXL_20210123_014851529.jpg
    PXL_20210123_014851529.jpg
    1,012.6 KB · Views: 30
You are gonna have more problems than that. Inner axle cup splines are different. You may be better off finding a 2g transmission.
 
Well, the car rolls, and the axles are in, how can I tell if they didn't swap the axles with the 91 with out taking it all apart? I'd hate to go hunt down a 2g tranny to find out it won't fit the 91 axles they swapped out...
 
Ok, disregard, looks like this bracket is just missing.
http://performancepartout.com/transmission-mount-bracket-087-2g-rear-manual/

I checked my tranny's code, and it matches a 95-99 FWD M/T per this thread:

https://www.dsmtuners.com/threads/axle-size-differences-emergency.69045/

You know what, I'm gonna stop posting until I get the engine out of this damn thing, cause I'm getting worked up about potential major issues that aren't major issues. LOL. Thanks for the help so far though, I'm learning a lot.
 
I've been searching these forums for a month, and last night was the first time I had something that actually correlated the tranny model number to specific years of eclipses. Most posts just say to use the search function, or that F5M33 is the FWD manual for turbos. And I thought it might be from a 91 because all the posts say don't do it because the mounts don't line up, and mine wasn't mounted.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top