I have an 86 rex...i want to know if i can replace my motor with a 89-91 rx-7....if so what will it involve, and 2nd question if i buy the md chip...and the safc from apexi will one cancel out the function of the other...any help will be greatly appreciated

 

I wuoldnt know for sure but common sense telz me that the md changes the timing and fuel but the afc changes just fuel so you can overide the chip with the afc and keep the auto adjusting timing(md) with your coolio fuel adjustments(afc) making it almost as good as a power fc.

 

Minimum you'd need the 89+ ECU and motor. I'd imaging the wiring harness is different as well.

I'm not sure if the 86 TPS, sensors, etc.. will work, so you might need those.

Personally I'd port/rebuild the 86 motor and get the racing chip you're talking about that's designed to go with the port.