S4 turbo two rx7 . Putting a s5 turbo two motor. What s4 parts are needed if any? Running all stock..
I have s4 t2 harness also but looks pretty warn. I don’t plan on spending much more on the vehicle and would like to do it myself.
so far I’ve got remove the ballast resister and block the omp and change to s4 wiring. Is there a simpler route?

 

I’m giving you an over simplified answer. This has been answered many times and there is good & detailed information on this forum from the past decades.

i have done this swap over 10 years ago, and easiest way is to use all s4 electronics on the s5 t2 keg with s5 turbo.
S5 omp will not work with the s4 ecu so premix will be needed or figure out swapping the front covers.
One issue is the increased compression ratio of the s5 rotors, my car seemed to not like the stock tmic and a fmic fixed it, and that was with a rtek ecu and safc. S4 ecu was designed for lower compression ratio and different split timing, the spark plug holes on the housing are literally spaced differently on s4 to s5.

So yes it will work, just be mindful of the differences to reduce the risk of pinging.

I could rant on about suggesting at least piggybacks like a fuel cut defender, safc, rtek ecu or move to a stand-alone ecu, wideband o2 sensor & gauge, etc. but all that info exists on this forum and you didn’t really ask for that.

 

So I’m told I will also need to change to s4 throttle body ,afm ,pressure sensor and change plugs, did you do this also? I figure there will be a few electronics that don’t quite match up either?
any other info goes a long way thanks starting the process this week. Less parts I gotta purchase the easier as I’ll be looking to pass the pits stock standard and after that willing to go further for performance stuff

 

yes, also ecu and tps.
There’s a recent thread where someone wired either s5 ecu to a s; car or vise versa. That’s another option. Back in the day with these parts easily available, it was just easier to swap electronics on the engine.