The little details are important!

[1970camaroRS]

Did some more logging and tuning yesterday. Noticed that when the tune was extremely rich the car ran significantly better. I'm talking a whole point in AFR. I did some thinking and read-up some more and wouldn't you know it, I missed a crucial step when tuning. Apparently the AFR gauge output is different when read on the gauge than when read by the tuner. Mine had a .5 differential so when I was commanding 12.8:1 it was really 13.3:1. Also, I was only logging 5 frames/second because I was monitoring too many data points. Got 20 frames/second by monitoring only the most crucial data. Started my tune from scratch and now the AFR is spot on (mostly...) and the car runs so much better in every way. WOT from low speeds blows away the tires now!

[Barry Donovan]

AFR monitoring is greatness...a chance anyway.

I found the little boxer likes a long strokes ratio, even being tiny engine.
bad choice for lean burn... the boxer

[1970camaroRS]

I just spent about 3 hours in the weeeee hours of the night driving and tuning and driving and tuning and driving and...

Car is pretty well dialed in with a open-loop MAF+SD tune. Smokes the tires at will...no hiccups, no hesitations, amazing throttle response. We shall see what it's like tomorrow in the heat.

[1970camaroRS]

I've been pretty busy and now I've got the AFR nailed down tight, including tuning in a lean cruise. Idle is 14.7 (18 degree timing), lean cruise is 16.3 (42 degrees), WOT is 12.7-13.0 (22 to 25 degrees). Throttle response is quick. Lights the tires at will. No knock retard. AFR is +/- .1 at all times. Only downside to the SD+MAF open-loop tune is that the AFR does drift a little bit when the ambient temperature changes dramatically.