Running A/C causes SD car to get real rich
07-20-2011, 12:11 AM
#1
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Running A/C causes SD car to get real rich With the A/C off my car will idle at 12.5-13 all day, but as soon as I trim on the A/C the AFR drops into the mid 10s at idle and part throttle.
I run a 3 bar SD tune using hptuners.
Any help would be appreciated.
I run a 3 bar SD tune using hptuners.
Any help would be appreciated.
07-21-2011, 08:02 AM
#3
Would certainly like to hear some opinions on this one, as I'm getting ready to connect AC to my 1-bar SD tuned LQ4.
It seems reasonable that the AC on is adding a load to the engine and VE values at X MAP vs RPM are different enough that it's throwing off your AFR's??? I would think the VE is much more sensitive with a boosted app too.
It might be interesting to do some VE error histograms with AC switched on VS AC switched off.
I am batting around the idea of turning on semi-closed loop in my tune. It might be enough to compensate for AC on if I experience the same conditions that you are, but I'm N/A so I have a feeling I won't see such a large swing (if any).
It seems reasonable that the AC on is adding a load to the engine and VE values at X MAP vs RPM are different enough that it's throwing off your AFR's??? I would think the VE is much more sensitive with a boosted app too.
It might be interesting to do some VE error histograms with AC switched on VS AC switched off.
I am batting around the idea of turning on semi-closed loop in my tune. It might be enough to compensate for AC on if I experience the same conditions that you are, but I'm N/A so I have a feeling I won't see such a large swing (if any).
