Gen2 - Gen3 engine swap

[Hrobinson]

Hi All
Over the last 5 years I have collected 3 SW20 MR2. All weren’t going, all with gen 2 engines with dropped bottom end bearings.

I have just put a imported low KM Gen 3 in one of them this week.

I’m using all of the gen 2 MR2 parts, loom, ecu, alternator ect.

Does anyone know if this is going to work?

All seems to be going together well, have had to make a few custom parts like some of the cooling fittings and extended the fuel lines to the fuel rail ect.

I know there’s a few post already on this issue but just wanted to ask the question?

Will it work?

Thanks
Hamish

[Hrobinson]

[GDII]

You need to run GEN2 pink injectors but other than that it should work.

[Hrobinson]

Nice.
Thanks for your help.
I should have 12 of them hanging around somewhere.
Cheers.

[mknz]

Doesn't the gen 3 have slightly higher compression? I imagine it runs rich and cool enough in NZ anyway that it's not a problem anyway

[GDII]

There is a guy in Wellington running this exact setup. Sure it does have higher compression but the GEN2 always runs rich anyway. Stinky old engines

[ClanFever]

You'll feel good having an mr2 you can finally drive! The gen 3s are nice little engines, you'll be able to have a blast for sure

[Benckj]

Although not essential the gen3 platform would go better if you had correct ECU. This would require a loom mod and upgrade from MAF to MAP. Might be something to consider in the future.

[GDII]

Gen2 NA is MAP already Jim. Plenty of things that can be done but dropping a whole GEN3 NA into the car and running the GEN2 NA electronics is the easiest way to make it run if you can't get GEN3 stuff.

Although I know where a GEN3 ECU is but sadly I butchered the harness for a GEN4 3SGTE swap. The GEN 3 NA ECU has 4 plugs so it's a little harder to get things working with a GEN2 harness. Probably repinning the harness can work if you have the plugs. I think I still have them in my parts box but technically they aren't mine. I'd have to ask the owner if you wanted to go down this route.

[Benckj]

I must be confused with the 3sgte gen2 being MAF. Been awhile since I’ve worked on the older NA’s. Thanks for the correction.

To save some googling, what is the power diff between gen 2 and 3? I seem to recall it’s about 20hp.

[mknz]

I just assumed it's turbo. Is it? or is it NA?

[GDII]

That's actually a good question. I was assuming again. Might need to get them to confirm if it's turbo or NA.

The car on the hoist was originally an Auto NA. But with these cars being so old you never know what was done.

[Benckj]

I just figured it was a NA due to the comment on gen 3 having higher compression. Believe the turbo ones actually went down a notch.

[GDII]

I just figured it was a NA due to the comment on gen 3 having higher compression. Believe the turbo ones actually went down a notch.

Yes the GEN3 3SGTE did drop compression a little bit. But it seems Michael and I both assumed it was NA. My reasoning behind my assumption was the bottom end bearings comment. Yes the GEN2 3SGTE can do it but it's a far less common occurrence than the GEN2 3SGE.

[mknz]

I was assuming GTE and thinking GE, my bad. OP's previous posts talked about getting an E153.

I'm guessing gen 2 electronics on a gen 3 GTE still works. Still probably be safe with the knock sensor hooked up, lower compression, and lower boost.