Has anyone done an accurate AFM signal map/table?


I've been trying to work out an interpolation table for my tech edge but its not going well. It seems to be a reverse V -> output table going from around 4v to 0.4v. It also does not seem to be linear at all. Its behavior seems exponential. Anyone out there have some ideas/help?

 

Well I plan on spending some time with this tommorow afternoon so hopefully i'll have smomething for you all, if anyone cares that is......

 

That would really come in handy for me. I plan to ditch the AFM and go to MAP with the eManage some time in the future. Think I will have to upgrade to the "Ultimate" version that has the AFM output table.

 

Yes I mapped it out. I'll have to check the data I collected for a project... I'm having trouble finding the data. Here's something I wrote though: the signals behave in a fairly linear manner in their critical regions of operation.

In other words I believe that the AFM was reasonably linear under driving conditions with respect to engine load. I'm not so sure about idle. If I can find any of the rest of my old data I'll post it.

Edit - Here's something else that I wrote:
The signal analysis has determined that any amount of throttle applied, alters the air-flow meter signal approximately 0.75V. The initial change contains the logarithmic region, beyond it the air-flow signal is semi-linear. It is believed that the project can proceed under this the assumption that the smallest amount of throttle will result in a 0.75V change and beyond this it is linear.

 

That's perfectly normal, so what's the problem?

 

I didn't say there was a problem. I was just mentioning what I observed.

 

wheres that map fellas???

 

The AFM voltage does drop when the opening gets larger. From my observations, the voltage output is pretty linear to me, down to 1000th of a volt so far.