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View Full Version : AEM ems: P/I control?



i3igpete
04-24-2012, 01:14 AM
Has anyone played around with the PI controls for the o2 feedback? Maybe used the Z-N tuning method?

I was playing around with some values and it looks they are way smaller than what is provided in the sample calibration. The pro tuner I used had both of these curves between 0 and -5 for most of the cruise range (and both around -10 at redline). For comparison the sample calibrations are typically between 0 and -10 in cruise, and both around -20 at redline.

Of course, I know it largely depends on the actual injectors, cams, o2 sensor type/location, etc. but just wondering if i'm in the same ballpark as others. The o2 feedback update rate also seems a bit slow on my car at ~200 millisecs. I know that this might be to dampen out the slower response of the AEM UEGO, but then why would the sample cals all have values in the range of ~70 millisecs (esp. if AEM engineers probably use the UEGO as a baseline?).

I don't mind running slightly smaller PI values, as long as I can safely update the correction rate.

Intropy
04-24-2012, 02:01 PM
Yeah 200ms seems slow. Mine is around 50ms I believe.

I played with it some just as a learning exercise (nothing formal like Z-N). I can't say that I ever got improved results.

i3igpete
04-24-2012, 02:21 PM
Where is your o2 sensor located? I just have a single wideband in the downpipe, which I'm guessing takes longer to respond than an o2 sensor in the stock precat locations.

Intropy
04-24-2012, 02:32 PM
Mine are about 12-18in away from the turbos. In the downpipe a few inches after the precats.