ive done alot of searching and got a pretty good idea about swapping either an sti or wrx engine in to the car. i am also swapping a manual trans in to the car at the same time. i only have a few questions that i really couldnt find any definitive answers on.
1. wiring - wiring is not a huge problem for me, certified in automotive electrical wiring and diagnosis and through frieghtliner but more towards the multiplexing side of things. anywho..... i have done tons of swaps srt in to older neons, hondas like there going out of style, northstar in to a jetta....and so on, but as of the subbie i get conflicted answers about harnesses. do i need a donor car for the harness? or can i splice in to the factory obs harness and repin the ecu connectors. i also can not seem to get a straight answer if i dont need a donor car for the harness...which harness do i use. motor obviously, but what else....
2. difference in the turbocharged ej20 and ej25... sound, performance, able to withstand abuse at times (voluntary fire fighter), aftermarket support between the two (im guessing they would be almost identical.)
3. drivetrain - im planning on swapping over to a manual trans. would like an sti drivetrain, but its not a MUST HAVE. i would be happy with just the wrx or with what i have now (minus the auto trans). once i do swap over though, i would have to switch the rear diff gearing out to match the front diff correct?
4. running cat less.. how to bypass the downstream o2 sensor without throwing codes, and without getting into the ecu. ive heard of the spark plug nofouler trick, but is this really effective?