I was wondering if anybody would be able to help me out with the tuning of the SAFCII? i just put it on and cant figure out how to tune it according to the manual. any suggestions or possibly pictures of a step by step afc tuning for a 91 s5 rx7?

 

there is a whole section of the of the forum for this.

 

You will need access to a wideband, preferably an on-board one. Basically you are going to go into the "setting" menu (after the unit has been configured) and then select the HI setting (high throttle). then you will reduce the airflow signal in the rpm range that is richer than you would like, usually over 5000 rpm. The effect will be less fuel and more advanced ignition timing in those areas.

 

so, on the bar graph in the hi throttle setting, do i want to go + or - to lean it out?

 

put it in the negative direction.

What you are really doing is reducing the airflow meter signal to the computer. So if the normal signal is 3 volts at that particular rpm and load, and you set it to -10%, the SAFC will intercept the 3V signal and reduce it to 2.7 volts.

What you have to remember though is that the airflow meter signal determines both fuel and timing. Generally speaking, "leaning out" the SAFC advances timing as well as reducing fuel, while "richening" the SAFC adds fuel and retards timing. This isn't that big of a deal on a non turbo, but on a turbo car you do have to be more careful.