I have an 86 FC base model, it's ready for a swap, but not sure if an turbo S5 will fit, so should I go with a turbo S4 or Trubo S5?

 

what do you mean its ready for swap. since your car is s4, get s4. it would be a lot easier

 

s4 and s5 turbo will fit equally well. s5 has more power stock, but some argue s4 is better for modding because of less detonation under higher boost (do a search and you'll probably find threads about this) So pretty much your choice, both being equally easy to swap, except if you're using the n/a drivetrian, you're going to need a s5 n/a flywheel and couterweight because of the lightened rotors on a s5. But then again, the n/a transmission is only good for 250 HP, so I'd swap the transmission too if you want to mod the turbo engine.

More info here:

https://www.rx7club.com/forum/showth...threadid=26647
http://www.rotaryresurrection.com/ro...conversion.htm

edit: fixed up my unclear wording

 

they will fit equally well, but if you get an s4 motor, you can use your ecu temporarily, althogh most ppl advise against this, i friend did this back home, and it ran pretty good.

 

thanks for replying, the package i'm purchasing actually include the s5 tranny and ECU and wiring harness, so I should be set right? will there be any problem with mounting the engine, like position wise?

 

thanks for replying, the package i'm purchasing actually include the s5 tranny and ECU and wiring harness, so I should be set right? will there be any problem with mounting the engine, like position wise?

 

are you putting it in a second gen? if so there will be no problem mounting, same spot, if its going in a first gen, than you will need different mounts, as first gens mount on the front as opposed to the middle. If you are getting ecu wiring harness and trans with the long block you are set. U just need some sensors if u dont already have them

 

if its a COMPLETE wire harness, not cut, you should be good. if not, break out the wire strippers/solder iron