So im wondering. If i put an SAFC on the NA can i adjust the the fuel map to get more power from the S4? If this is possible..... Does anyone know where the safe fuel levels are? I want to get as much out of the NA setup as possible without getting the big bang.

 

you will be better off with a real ECU. Using the SAFC is like putting a band aid on a zit, it does little good and makes things more awkward.
On an all stock S4 you will not get much more power either way, but you can get an ok boost in MPG.

 

well thats good news about the mpg. My 7 is my daily so a lil better mpg would help out a bit. It would also be nice if i stumbled across an ecu that wasnt hindreds of dollars.... but what can you do. I guess ill use the bandaid until i get enough insurance to see the doctor.

Still tho, any ideas of where i can find a safe fuel range? would love to have a better idea of where the AFR should be, without doing damage to the engine

 

the answer is yes but not much. i have an otherwise stock original low miles s4 na

MPG 2% less fuel = 2% more mpg? = 2% of 18mpg is .6mpg... don't get me wrong better MPG is better MPG.

the fist step i took tuning mine was trying to get as little exhaust back pressure as possible, then i played with the timing, then played with the fuel. so my changes with the AFC were small and mine wasn't that rich.

i did lean out a couple of richer spots, it really helped the 6500-fuel cut range and the 3500-4500 range.

so overall my car gets better mpg and power than it did before, the AFC was just a part of that