Is the AFM absolutely necessary? I can't seem to find a thread about it.

 

On the stock ecu yes.

 

so if you have a stand alone you don't need it? just want to make sure.

 

Yes. A standalone EMS usually runs in speed-density mode, which means it uses engine rpm and manifold pressure to calculate the airflow rate as opposed to using an AFM. The auto shop that you are paying to install and tune the standalone EMS should explain this to you, along with the features that you will gain and lose by converting to the standalone EMS.

 

I'm actually not using a stand alone. I just want the knowledge. On another note, can a single AFM be used for each model? Say between NA's and TII's as long as you modify the plug.

 

No, there is a different AFM for NAs, turbos, S4s & S5s. The plugs are the same within series.

 

I was just curious. Thanks for the info guys.