Personally which system is easier to install. (talking about hours of work with wire splining etc.) and does anyone know any reliable fuel and ignition maps?

 

A piggyback ECU (S-AFC) or reprogrammed ECU (R-Tek) is the easiest to install. A plug-in EMS would also be easy, but unfortunately none are offered for your S4 RX-7 at this time. However, Wolf is supposedly offering a V500 plug-in kit in the near future. Other than the plug-ins, every other brand and model of universal EMS requires pretty much the same installation effort.

Also keep in mind that setting up a universal EMS is very difficult. The user is required to program the proper engine type, number of cylinders/rotors, ignition type, and many other parameters that are very confusing to the casual car owner. It is a good idea to read the manual of an EMS before you buy it, as simply setting it up for a rotary engine may be more work than expected. A dedicated standalone EMS (Microtech) is already set up by the factory, but keep in mind that it will not work with any other type of engine unless it is sent back to the factory for reprogramming (which usually costs several hundred dollars).

If you are not willing to pay for professional EMS tuning, then you would be better off sticking with the R-Tek or stock ECU. Somebody else's speed-density EMS map may allow your engine to run, but it will not exactly match, and may even ruin your engine. The speed-density system used by most standalone EMS products does not compensate for small variances like the stock mass airflow system.

 

Thanks for the info