Open loop to closed loop transition - time related? Tephra V7
#31
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Basically am I just looking for irregularities at certain RPM between the Wideband AFR and also the Air Flow Hz? i.e. If the Hz is at 200, the RPM is at 2500 and the AFR may suddenly go to 12.5 when it mainly averages 14.7, then I scale it down slightly in the 'Maf Scaling' under global fuel settings? Should I also be comparing adding the TPS into the equation to ensure its at the same position? When would you increment the change in the certain cell? And what is considered as a significant AFR drop, 1 full point, .5 points etc?
So, what you would do, is just do a steady cruise at different RPM values (to be at different Hz values). Try to stay at that RPM (Hz) value long enough to stabilize the AFR to see how far off from 14.7 it is. Try to do that for as many Hz values as you can. Now, you have the data to adjust your maf tables.
I would suggest to just use your maf smoothing table and leave maf scaling alone. Your maf smoothing table may be listed as maf compensation, depending on which XML you have. The reason I say to use MAF smoothing is because it's just used to adjust the IPW and wont affect the load (if I remember correctly). Since all you care about is fuel here, just use that table.
For adjustment, if you're rich (ie 12 AFR), adjust the number for the Hz cell down. If you're lean (ie 17AFR), adjust the Hz cell number up. As far as what is far enough for adjustment...that's your call. If would say within 5-10% is good. Obviously the tighter, the better, but it will be difficult of course to get it perfect.
Also, for future guidance. Since you're on E85, if your cold starts or warm starts begin to be a but troublesome, just use your IPW cranking tables and remember this....E85 needs more fuel when cold, but needs less fuel when warm.
Good luck with everything. Looks like you're on your way. Now you can be your own tuner and do a better job than the person who previously tuned you.
Oh, also, since you originally stated that you were tuned at WOT, since we changed your injector scaling to what it should be, your WOT is no longer tuned. You will need to use your fuel maps now to bring that back to the AFR that you want. It should be richer now at WOT until you tune it back to what you want.
Last edited by l2r99gst; Aug 4, 2011 at 05:54 AM.
#32
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The XML I have lists it as 'Maf Compensation. Looks pretty straight forward.
Should I be re-scaling if the following scenario occurs?
Driving steady at a certain RPM, the AFR sits say 14.7, then might drop to 12.5 for 3 or 4 seconds and go back to 14.7, but the HZ is still the same?
l2r99gst your a champion and thanks heaps for helping me setup my fueling issues and given me a platform to start from. Those extra tips about the fueling for cold and hot will definitely come in handy
Should I be re-scaling if the following scenario occurs?
Driving steady at a certain RPM, the AFR sits say 14.7, then might drop to 12.5 for 3 or 4 seconds and go back to 14.7, but the HZ is still the same?
l2r99gst your a champion and thanks heaps for helping me setup my fueling issues and given me a platform to start from. Those extra tips about the fueling for cold and hot will definitely come in handy
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