Apexi S-AFC Setting

[1997GS-T]

I finally got my Air flow reading registering as I have set the thing to a Karmon type. What is the reading meant to be for optimum running at different RPM?

 

[HPF_MK3T]

Actually, it will be different from car to car depending on mods, engine condition, and fuel system. You shoud really only tune the AFC on a Dyno or with a wideband o2, such as a FJO or a "Do It Yourself" kit. You don't want to do it by a "seat of the pants" tuning method or EGT or A/F gauge that uses o2 voltage.

Seat of the Pants is the worse way because it can still feel good and be running way too lean. Most power is produced on the verge of detonation.

EGT gauges don't react fast enough if you run too lean. It can take up to 2-3 seconds for it to react to exhaust changes under full throttle.

A stock o2 operates from 0-1 volt, where .2-.8 volts is Stoich (14.7:1), and .8v+ is 10:1-14:1 a/f, and .2v- is 15:1-20:1 a/f, plus the factory o2 is affected by exhaust temp.