AFC 2 Karman Hz reading?

[bpclements]

Just curious if anyone has any knowledge on tunning with the Hz reading? I just read an article from Modified by AMS. They say that the higher the Hz the richer you are running. I have never observed my Hz before because I had no clue what it meant. I might actually take a look at it and see what mine is running. I wonder how good I can log Hz on the AFC? It's worth a shot.

[Claudius]

Originally posted by bpclements
I just read an article from Modified by AMS. They say that the higher the Hz the richer you are running.

[L2RTSiAWD]

Ya that's not right at all.

The Hz is just measuring the airflow coming thru the MAS, it doesn't have anything to do with a rich or lean condition.

[bpclements]

Cool. Thanks for clearing it up.

[12secEVO]

hmm, I'm sure it would help for problems with fuel cut. Because fuel cut is based on air-flow. You can trick the ECU into thinking that there is actually less air lets say 2500hz is fuel cut...and you are just barely getting into it...you trick the ecu into thinking it is 2400hz (i'm not sure if higher or lower is more flow?) then richen it up a bit to make up for the extra air. then wow, no fuel cut and a damn fast car.

[Fourdoor]

Originally posted by 12secEVO
hmm, I'm sure it would help for problems with fuel cut. Because fuel cut is based on air-flow. You can trick the ECU into thinking that there is actually less air lets say 2500hz is fuel cut...and you are just barely getting into it...you trick the ecu into thinking it is 2400hz (i'm not sure if higher or lower is more flow?) then richen it up a bit to make up for the extra air. then wow, no fuel cut and a damn fast car.

How are you planning to richen it up? Most A/F controlers (like the SAFC) don't actually change the injector pulse width directly, the change the HZ reading supplied to the ECU. To make it richer they fool the ECU into thinking there is more air flow to make it supply more fuel....

The EVO runs so rich stock that you can take out a LOT of fuel at high RPM without encountering detonation... this has the pleasent side effect of putting you further away from the fuel cut threashold, AND as far as the ECU is concerned you are at a lower load point also, so it puts you at a more advanced timing setting.

Keith

[12secEVO]

i really shouldn't be replying to afc related threads, I'm sorry, I was thinking that fuel adjustment was a seperate thing all together.

I'm just used to DSMLink where fuel, timing, VE, and Airflow hz were all seperate adjustments...and I never touched the VE and airflow. So I'm going to stop replying to AFC threads that I'm not sure about until I've acutally started using one...sorry again guys

[Claudius]

Keith is right. The S-AFC is simply a MAS controller.

A PowerFC would enable you to have control over injector pulse and ignition timing.