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Re: Comments about this data plot - AFR danger
Bob, no answer, just "newbie's" question here: Are you referring to the saw tooth pattern of the torque curve?
I am calling a flutter. 
Kidding aside -- is it not the clutch slipping? Or I assume from title of thread and the AFR curve, something "bad" happens at 5400 rpm? The sudden drop implying something "mechanical," not software related?
--
Regards,
Can
997 Turbo + Bilstein Damptronic "Stage 2" ( Review ) + GIAC ECU Tune ( Fast as a torpedo & reversible to stock - Review ) + Cargraphic Exhaust ( Oh heavenly noise! )
Re: Comments about this data plot - AFR danger
cannga:
Bob, no answer, just "newbie's" question here: Are you referring to the saw tooth pattern of the torque curve?
I am calling a flutter.Kidding aside -- is it not the clutch slipping? Or I assume from title of thread and the AFR curve, something "bad" happens at 5400 rpm? The sudden drop implying something "mechanical," not software related?
The AFR curve represents the air/fuel ratio, which suddenly gets very rich at around 5400 rpm. This will have been determined by the injection mapping, so it is software-related.
This engine is liquid-cooled, but I didn't think that this implied that you had to use fuel to cool it. 
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fritz
Re: Comments about this data plot - AFR danger
The plot comes from a friend who recently purchased my 997TT - I'm in the process of sorting things out. I was quite surprised at the results of the dyno. I suggested changing plugs and coils, then rerunning the dyno with 94.
More to come...
Re: Comments about this data plot - AFR danger
fritz:
cannga:
Bob, no answer, just "newbie's" question here: Are you referring to the saw tooth pattern of the torque curve?
I am calling a flutter.Kidding aside -- is it not the clutch slipping? Or I assume from title of thread and the AFR curve, something "bad" happens at 5400 rpm? The sudden drop implying something "mechanical," not software related?
The AFR curve represents the air/fuel ratio, which suddenly gets very rich at around 5400 rpm. This will have been determined by the injection mapping, so it is software-related.
This engine is liquid-cooled, but I didn't think that this implied that you had to use fuel to cool it.
Thanks Fritz. The AFR's stair step drop looks so much like something mechanical just "snaps," but I see what you mean. What do you think of the saw tooth pattern of the power curve? I wonder if this is the cause of the AFR dumping later as engine RPM climbs?
Bob, you still have that spare ECU? How about switching to stock ECU and re-run the data logging? Wouldn't this be the easiest diagnostic step?
--
Regards,
Can
997 Turbo + Bilstein Damptronic "Stage 2" ( Review ) + GIAC ECU Tune ( Fast as a torpedo & reversible to stock - Review ) + Cargraphic Exhaust ( Oh heavenly noise! )
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