Did some searching but didn't get the information I wanted. I know the basic engine and turbo is the same but all the posts made mentnion of the fact that there are some other suble differences dealing with emissions etc. Can anyone tell me what these differences are? Got a 90 T2 jdm engine setup to put in one of my first gens, just trying to learn all I can about it before doing the swap. Thanks guys
Sean

 

On S5 Turbo models I don't think there are any differences, other than in emissions equipment there is no pre-cat.

Now S4 models have more Aspec vs Jspec differences, like no EGR, no pre-cats, etc.

 

This has been discussed soooo many times...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/us-vs-japan-fc3s-490591/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/usdm-vs-jdm-13bt2-408897/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/difference-between-usd-jdm-299458/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/whats-difference-between-2-a-287616/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/difference-between-j-spec-us-spec-2nd-gen-74672/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/jspec-horsepower-254724/

 

Basicly you get to say you have a JDM motor and think your cool

btw i have a j-spec motor in my a-spec 7 it's the same as taking off your emition stuff on a a-spec and in some states you can't get your tagged renewed with out emitions

 

Or you get to tell people you have a JDM motor and people know your going to be rebuilding soon.