1G 1992 Eclipse GS 2.0 N/T to Turbo

[Nick903@]

Yes, I know this has been covered but not entirely answering my question. Kinda just need to vent out my thoughts and have a opinion on it.

So I have a 1992 Eclipse GS 4g63 N/T with auto trans. I want to go the turbo route with it. Yes I know pistons, cams, etc are different and it needs oil squirters. Regardless, if I had a turbo motor already or not I still want to go head and put stronger rods, pistons, cams and build the head, etc. I was planning to buy a harness due to the fact the dash is cracked and wanted to find a nicer one around so to save me time. I’ll go ahead and replace the harness just wanting to know if my plans are to build the N/T motor would it make really a difference between the two.

Not asking for any negativity just needed true opinions on this. I’ve owned 5 GST, this is my first 4g63 N/T and want to feel insured. Yes, it is a 6 bolt.

Question, is it really any different then just building a Turbo version than the N/T version, if plans are to build it anyways. Am I going to be spending more out of pockets etc.

 

[92AWDHX40]

Not being negative but build the non turbo into what. Exactly its kind of confusing what you are asking to do I did the swap just to have a turbo .

 

[Spleen8urLSX]

It doesn’t NEED oil squirters, some builders actually prefer the nt blocks for this reason, that’s more of a preference. David Buschur had a video where he explained his reasoning for this in the earlier days of YouTube and before pickins were much more slim they actually preferred the non turbo blocks for their customer builds for this reason. Again, that comes down to preference, but I’ll vouch from personal experience I never had any issue from making power with no oil squirters and I’d average about 4k street miles a season while beating the bajesuses out of it.

Not saying EVERYONE should do it and it would work out for everyone, but I threw boost at my untouched non turbo bottom end for about 20k miles, 3 out of those 4 seasons making over 400 at the wheels, the last time it was on the dyno it made 454 on pump gas, prior to that it had made over 400 on e85. At that point I didn’t care as that engine owed me nothing but I had every intention of throwing 600 at it on e85 just to do it but unfortunately it had a mishap. Seal on the oil filter blew mid pull with my buddies wife’s 3v Mustang on Cosby juice starved it of oil and wiped out a balance shaft bearing and oil pump, pistons from that engine still look good. I’d do it again and not think twice about it, at that point it’s no different from those throwing power at stock turbo pistons, one error with detonation and they’re as big of a risk. Again not saying everyone should do this, but I learned enough doing it to debunk the old “anything more than stock boost from a 14b will crack the ring lands!!” myth from 20 years ago when technology was much different thought of by those who hadn’t done it.

As far as differences between the 2 variants that’s been discussed numerous times over the past 20+ years, but for quick reference literally the only internal differences aside from the lack of oil squirters are the pistons and one of the camshafts as you mentioned and also the nt blocks gave a slightly tighter bore. When building one it comes down to no different than building any other 6 bolt 4g63. Crank and rods are the same, head and valvetrain are the same, etc. The biggest mistake I’ve seen made after @1qkfwd pointed out the bore size is many thought they could simply hone the cylinders and slam stock replacement turbo pistons in the nt block when machining the cylinder bores to proper size is required. The engine I’m building now was a living example of this but has now been bored to correct the vertical gouging that was caused by someone attempting that. Other than that, no different when it comes to building. Of course there’s zero harm in going with a set of h beam rods and forged pistons for reassurance and to be able to reliably hold more later if you want, but if you were to decide stock rods are sufficient for what you want to do (if you’re never planning over 500ish than anything other than stock 6 bolt rods aren’t necessary anyway) then the rods you have would be fine to use assuming they check out as they are no different from the turbo variant. As far as the crank goes again, rarely does one need anything other than a stock crank as the stock crank is proven to 1000+ no problem, so assuming yours is in good condition it will be fine for whatever you’re looking to do as again no difference from the turbo variant.

I seen you mentioned the car is an automatic, I will say if you choose to stay automatic you’ll need to source a trans from a fwd turbo 1g or go with a 2g auto trans. The fwd turbo 1g trans will hold the power no problem but they’re hard to come across these days (I know a guy with a shelf full and he doesn’t sell them for this reason) but would be a direct bolt in for your auto trans. The 2g fwd auto can be used but I don’t know the exact ins and outs of using it however it is much easier to locate one. The nt auto trans you have now wont hold up to any power, a few have tried it and it resulted in the trans just slipping when trying to roll into boost. If you swap to a manual again, will need a fwd turbo trans whether it comes from a 1g or 2g as the nt manual trans doesn’t like power either.

Lastly, wanted to give the same advice I give everyone when it comes to the harness. Don’t change it. It is much easier to add the couple wires you need than it is to buy a good unhacked 30 year old harness, fish your harness out breaking a few brittle otherwise good 30 year old plastic connectors, then fishing a new one in likely breaking 30 year old connectors on that one in the process requiring you to repair it once it’s in. If you end up using ECMlink or Linkecu G4 right off the rip with high z injectors and speed density then most of the wiring wouldn’t be needed. I’ve seen this several times where someone converts one of these cars and goes that route thinking the turbo wiring harness would benefit them for some reason, and all they end up doing is spending a couple hundred bucks to cause themselves a bunch of headache and time and broken stuff that didn’t need to get broken all to come out with a bunch of extra crap on their harness they aren’t using anyway. Any wiring that needs done is super straight forward and simple and can be walked through within a few minutes.

 

[Nick903@]

Lastly, wanted to give the same advice I give everyone when it comes to the harness. Don’t change it. It is much easier to add the couple wires you need than it is to buy a good unhacked 30 year old harness, fish your harness out breaking a few brittle otherwise good 30 year old plastic connectors, then fishing a new one in likely breaking 30 year old connectors on that one in the process requiring you to repair it once it’s in.

Highly appreciate it do u have the wiring diagram for the pins etc

 

[Spleen8urLSX]

I do not have it handy however the 91-94 ECU pin out is widely available on here. The pin out for the 91-94 N/T 4g63 and turbo are the same with the exception the turbo variant has a few things added that are otherwise empty pins in the non turbo harness which is what makes it so simple. This is where it depends on what you will actually be using.

In short, if you were to use a stock 91-94 turbo ECU (not utilizing ECMLink and speed density) that’s where it becomes more necessary. There are 2 things you have to add, the “MAF signal reset” wire and the knock sensor signal wire. All I did was use a junk harness I had laying around and cut these 2 wires back a few inches from the ECU connector then de pin them from that harness then added them into my harness at the ECU connector. Then you have the maf sensor pigtail, on the non turbo harness it’s a 6 pin connector with 6 wires, on a turbo harness it’s an 8 pin connector with 7 wires. I clipped the MAF pigtail off of the junk harness and clipped the nt maf pigtail off the cars harness, on a 91-94 you're left with wires that match up color wise with the turbo pigtail, there’s plenty of diagrams to show the pin out but the simplest way was to match the colors of the wires on the cars existing harness to the wires on the donor pigtail, that leaves one wire left over on the turbo MAF pigtail, that’s the “MAF signal reset” wire I spoke of that’s an empty pin in the non turbo harness. All I did was simply solder a wire to the one I clipped into that pin and run it out into the engine bay then solder it to the left over wire on the new turbo MAF pigtail and that covers that part of it.

For the knock sensor, I also robbed the knock sensor pigtail off of the junk harness. There’s 2 wires to this pigtail, one is your knock sensor signal and the others a ground. On a turbo harness that ground wire grounds to a shielding on another wire, the non turbo harness won’t have that grounded shielding. Not an issue, all I did was simply solder a wire at the cut wire I added to that pin from the donor harness and run it out to the signal wire on the knock sensor connector, then for the ground wire on the connector I ran a wire in under the dash with a ring terminal on the end and found a good spot to ground it, that covers that.

After that is wiring in the injector resistor pack if you are using low z injectors. That DOES NOT wire to the connector at the ECU, I used a diagram made by someone here many years ago and wired it in according to that diagram, as all the resistor pack is essentially doing is intercepting a 12v signal to the injectors and adding resistance.

Now as I mentioned, depending on how you do it much of that isn’t necessary. For example, if you were to use ECMLink and speed density right off the rip speed density doesn’t utilize the “MAF signal reset” pin, therefore there’d be no reason to run that wire as it’s not doing anything, you could simply splice in a turbo MAF pigtail matching the wires up to make the plug and play speed density harness plug in as it should and leave it at that, or you could get froggy and get the pin outs and cut the MAF pigtail off and wire a GM IAT sensor pigtail and MAP sensor pigtail directly to the proper wires and be wired for speed density without the use of a plug and play harness.

If I had it to do over again I would’ve still wired in the turbo MAF pigtail but I would have depinned the non turbo one and pinned in the turbo one to make it a bit cleaner and look untouched but soldering the wires works fine nonetheless. Same with the knock sensor, many will debate it and that’s an argument for another thread, but many using ethanol fuels or race gas only anymore opt to not use the knock sensor and using ECMLink or a plug and play standalone gives the option of not using it, therefore if one was to decide against using the knock sensor there’d be no need for that wiring.

With that being said when using high z injectors that eliminates the need for the resistor pack, therefore no need to wire that in at that point. So in short, if you were for example running ECMLink with speed density and the plug and play SD harness, for example high z 1650cc injectors, and had opted to use e85 and your tuner was fine with not utilizing a knock sensor, the wiring would be as straight forward as simply wire in a 1g turbo MAF pigtail in the engine bay in place of what was there and DONE, everything else would be direct plug and play.

Also, a junk harness or donor isn’t necessary to obtain the connectors and pins. The connectors and empty pins are available new from OHM racing, I just used a cut up junk donor harness with these things already on it since I had it readily available and everything right in front of me.

 

[92AWDHX40]

Its online how to under non turbo swap dsm.

 

[Nick903@]

I do not have it handy however the 91-94 ECU pin out is widely available on here. The pin out for the 91-94 N/T 4g63 and turbo are the same with the exception the turbo variant has a few things added that are otherwise empty pins in the non turbo harness which is what makes it so simple. This is where it depends on what you will actually be using.

In short, if you were to use a stock 91-94 turbo ECU (not utilizing ECMLink and speed density) that’s where it becomes more necessary. There are 2 things you have to add, the “MAF signal reset” wire and the knock sensor signal wire. All I did was use a junk harness I had laying around and cut these 2 wires back a few inches from the ECU connector then de pin them from that harness then added them into my harness at the ECU connector. Then you have the maf sensor pigtail, on the non turbo harness it’s a 6 pin connector with 6 wires, on a turbo harness it’s an 8 pin connector with 7 wires. I clipped the MAF pigtail off of the junk harness and clipped the nt maf pigtail off the cars harness, on a 91-94 you're left with wires that match up color wise with the turbo pigtail, there’s plenty of diagrams to show the pin out but the simplest way was to match the colors of the wires on the cars existing harness to the wires on the donor pigtail, that leaves one wire left over on the turbo MAF pigtail, that’s the “MAF signal reset” wire I spoke of that’s an empty pin in the non turbo harness. All I did was simply solder a wire to the one I clipped into that pin and run it out into the engine bay then solder it to the left over wire on the new turbo MAF pigtail and that covers that part of it.

For the knock sensor, I also robbed the knock sensor pigtail off of the junk harness. There’s 2 wires to this pigtail, one is your knock sensor signal and the others a ground. On a turbo harness that ground wire grounds to a shielding on another wire, the non turbo harness won’t have that grounded shielding. Not an issue, all I did was simply solder a wire at the cut wire I added to that pin from the donor harness and run it out to the signal wire on the knock sensor connector, then for the ground wire on the connector I ran a wire in under the dash with a ring terminal on the end and found a good spot to ground it, that covers that.

After that is wiring in the injector resistor pack if you are using low z injectors. That DOES NOT wire to the connector at the ECU, I used a diagram made by someone here many years ago and wired it in according to that diagram, as all the resistor pack is essentially doing is intercepting a 12v signal to the injectors and adding resistance.

Now as I mentioned, depending on how you do it much of that isn’t necessary. For example, if you were to use ECMLink and speed density right off the rip speed density doesn’t utilize the “MAF signal reset” pin, therefore there’d be no reason to run that wire as it’s not doing anything, you could simply splice in a turbo MAF pigtail matching the wires up to make the plug and play speed density harness plug in as it should and leave it at that, or you could get froggy and get the pin outs and cut the MAF pigtail off and wire a GM IAT sensor pigtail and MAP sensor pigtail directly to the proper wires and be wired for speed density without the use of a plug and play harness.

If I had it to do over again I would’ve still wired in the turbo MAF pigtail but I would have depinned the non turbo one and pinned in the turbo one to make it a bit cleaner and look untouched but soldering the wires works fine nonetheless. Same with the knock sensor, many will debate it and that’s an argument for another thread, but many using ethanol fuels or race gas only anymore opt to not use the knock sensor and using ECMLink or a plug and play standalone gives the option of not using it, therefore if one was to decide against using the knock sensor there’d be no need for that wiring.

With that being said when using high z injectors that eliminates the need for the resistor pack, therefore no need to wire that in at that point. So in short, if you were for example running ECMLink with speed density and the plug and play SD harness, for example high z 1650cc injectors, and had opted to use e85 and your tuner was fine with not utilizing a knock sensor, the wiring would be as straight forward as simply wire in a 1g turbo MAF pigtail in the engine bay in place of what was there and DONE, everything else would be direct plug and play.

Also, a junk harness or donor isn’t necessary to obtain the connectors and pins. The connectors and empty pins are available new from OHM racing, I just used a cut up junk donor harness with these things already on it since I had it readily available and everything right in front of me.

Thank you

 

[92AWDHX40]

Www.angelfire.com has the link you need

 

[Spleen8urLSX]

Www.angelfire.com has the link you need

Yes and no. I used that link when I converted mine, but 75% of it is either inaccurate now due to lack of knowledge back then or technology advances since his write up 20 years ago, and the other side of it a lot of different things are available. My explanation covers most of the usefulness of that write up, but the vast majority of it is irrelevant now and a few things that weren’t even correct come to find out later. However as far as wiring it’s a good reference for wire colors and what not.

 

[Nick903@]

Anyone around Dallas Tx area know good recommendation for machine shop need my block built I’ll be supplying parts etc ???

 

[Nick903@]

What’s pistons should I go with

Wiseco Forged Pistons w/ Rings (9.0:1 C.R.):
90-92 Mitsubishi Eclipse 6-Bolt

OR

Wiseco Forged Pistons w/ Rings (8.3:1 C.R.):
90-92 Mitsubishi Eclipse 6-Bolt

Also are the rods a most to upgrade only looking for no more then 500Hp

Suggestions???

 

[BLACK'98DSM]

If you swap to a manual again, will need a fwd turbo trans whether it comes from a 1g or 2g as the nt manual trans doesn’t like power either.

Now I know some of the non turbo models came with the turbo trans. For example my '92 Eclipse GS was fitted with a turbo 5 speed from the factory. I'm not sure what was the determining factor between using each of the transmissions originally but you can't say NONE of the N/T transmissions will work when some of them are the exact same. It can be verified through the VIN number of the car, forgetful of which digits though.

 

[Spleen8urLSX]

Now I know some of the non turbo models came with the turbo trans. For example my '92 Eclipse GS was fitted with a turbo 5 speed from the factory. I'm not sure what was the determining factor between using each of the transmissions originally but you can't say NONE of the N/T transmissions will work when some of them are the exact same. It can be verified through the VIN number of the car, forgetful of which digits though.

First I’ve heard or seen of this but let me change my wording then. IF the car has a factory f5m22 (aka the non turbo trans) it will technically work I should have said, but throw 18lbs from an evo 3 16g and try to shift it wide open and it hates its life (take a wild guess how I found that out).

In 17 years of messing with these I have never seen a 1g non turbo with a factory f5m33 and stepped flywheel, between working on them, owning them, and robbing parts off them in the boneyard, every single one of them has had an f5m22 if they were a manual car. Now that’s not saying you’re wrong, but if that stands true it’s a real rarity and I’d be curious to know their thought process behind placing a transmission in those few cars with non optimal gearing for the application, only thing I could see is a vert few oddballs out there ended up with the f5m33 due to supply issues and what they had on hand to complete a production run. I’d like to see further documentation on this now as I’m genuinely curious. I could also see this being true in the Euro models as they did share some oddball component’s with their Turbo counterparts that the US nt’s did not, but that’s irrelevant here in the US.

Either way, the OP has the non turbo automatic transmission, so either way we know that’s not going to work out for what they’re looking to do as mentioned above.