Hey all. New username here. Been away from the site for like 12 or more years as life just sorta happened. Back now and the fiance has an interest in my old 87 White S4. I have a 13B in my 89 Vert and was curious about compatibility. My goal is to eventually put a TII in the Vert. The engine on the 87 is bad. I'm considering getting my ducks in a row and seeing if I can just plop the 89 13B into the 87 with minimal issues. I looked for info on the FAQ but the links available were dead. Can anyone enlighten me on the process or it if would just make more sense to have the 87 engine rebuilt. Thanks and glad to be home.

 

https://www.rx7club.com/2nd-generati...or-s4-1014003/

 

S5 engine harness wired up to s4 dash and front harness is a nightmare.

I have a s4 na chassis where I installed a s5 t2 keg. I used s4 t2 electronics to make everything jive. Worked great. Years later I have rewired the whole car with s5 chassis and dash wiring harnesses due to cali smog BS to run s5 t2 n370 ecu.

Im not too familiar with N/A engine stuff but the easiest way may be to use the s4 electronics on the s5 engine.

 

S5 drops in the S4, use S4 harness on the S5 block. a few sensors toy will have to either use a bullet connector and a connector as a adapter on the water temp on the block under the oil filter. You can change over Intake manifold or do the mod for the aux ports to come open or pull sleeves but Throttle Body is needed due to the T.P.S. on the S5 is different from the S5. OMP will only work via swapping front cover or hang wires for the OMP out the way and run premix, 1oz per gallon. Swapping the fuel injectors because physically the injectors via early S4 86-87 are Low Imp while late S4-S5 use Hi Imp injectors. Did a S5 JDM swap in 2011, so the the use of the S4 wiring harness makes the process easier.