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View Full Version : clarification on semi closed loop SD



Cablebandit
October 5th, 2009, 10:44 AM
I have COS5...everything runs pretty good in OLSD. I daily drove it this way and have run at the track this way for a few years. Today, I put my o2s in and set every cell from 0-75kpa and 0-2800 rpms to 14.63 commanded afr (commanded afr vs rpm table) . I noticed the STFT adjusting (LTFT at zero and disabled) and wideband is pretty stable around 14.7. I figure this will give me good/stable fueling at idle and cruising. What I do NOT want is the o2s to affect my WOT in ANY way. Do I have this setup properly?

My scans today always report Open Loop and LTFT at zero since they are disabled but I do get STFT corrections now. It SEEMS the STFT hit zero when i go 100% tps while idling but since its raining I didnt get to try it on the street. I want ZERO o2 influence on my WOT.

Thanks

joecar
October 5th, 2009, 01:24 PM
It seems you are setup correctly...

the B3647 WOT cells (>80kPa, >5000rpm) would be richer than stoichiometric (14.63), so semi-open loop will not affect WOT...

semi-open loop only enables for those cells set to stoich afr (0-75kPa, 0-2800rpm in your case);

semi-open loop uses STFT's to trim.

Cablebandit
October 5th, 2009, 01:51 PM
thanks thats what I thought. I want to see if the O2s can get my mileage better with the weather swings here in Ga