From
http://www.toyotacelicaonline.com/celica1/3sgteswap.htm3S-GTE Swap
In this space I would like to have a complete writeup on a 3S-GTE swap. The 3S-GTE is a the potent engine found in the All-Trac/GT-4 Celicas and Turbo MR2s. With anywhere from 180-260 Hp from 2.0L (and potential for far more) it is one of Toyota's most potent 4-cylinders out there. The good news? ...the 4-6th generation Celica chassis was built to take the engine and it bolts into existing engine mounts (for those with the 5S). The bad news is the cost...expect to spend at least $5000 for the swap. Until I get a complete write up from someone who has done the swap I will use this page to answer some of the common questions, and address some of the issues that arisewith the 3S-GTE swap.
What engine choices are there?
From my understanding there are 3 generations of the 3S-GTE offered either domestically or abroad.
1st Generation (190 HP) 1988-89 ST165 (Celica GT4/All-Trac)
2nd Generation(200 HP) 1990-93 ST185 (Celica GT4/Alltrac)
1990-199x(?) SW20 (MR2 Turbo)
3rd Generation (260 HP) 1994-99 ST205 (Celica GT4)
Note: not released in U.S.
Needless to say that each generation had significant improvements over the last (such as larger throttle bodys, better turbo and intercooler designs) and it is better to go with the later versions if possible. Unfortunately, the third generation was quite rare (meaning pricey) and for those of you who need to meet emissions in the US...this engine was never tested, and it may not meet national requirements (but more on that later...). Even rarer versions were sold in the 2500 or so cars sold under the Carlos Saintz/Group A/RC names which were fully built rally motors with a few advanced features "turned off" or present but not functioning.
How is the transmission handled?
Well, the 3S-GTE does bolt on to and works with the transmission that comes with the 5SFE (2.2L). Whether it will last under the additional power, it is not known. Unfortunately as far as I have heard...Toyota never mated the 3S-GTE to a FWD transmission. If you choose to use a stronger transmission you can use either the transmission from a MR2 or the rare V6 Camry transmission, both of which bolt on to the 3SGTE engine
Blkrx7 notes that if you do choose to use an MR2 tranny as opposed to one from a GT-Four:
Hoses don't line up of course, they use diffrent spigots on the MR-2 motor to line up with those hoses. The I/C is useless, and a couple of systems (like the intake) are in slightly different locations. It makes for more headache.