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Wot a/f ?

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Old 02-24-2010, 12:42 AM
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I absolutely loathe DFCO. I hate the engine braking feel. Mine is disabled of course.
Old 02-24-2010, 02:55 AM
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Yea, just let me know and I can get that ordered.


My DFCO is disabled. I like it to be able to coast a ways. sometimes i'll even put it in neutral if i'm going down hill and there's a stop sign at the bottom.
Old 02-24-2010, 07:52 AM
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yeah i will let you guys know and i would want that turned off i like to coast also.
Old 02-24-2010, 09:27 AM
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My DFCO is disabled as well, but still at the end of a long WOT run like at the end of the track when I close the throttle quickly it jumps way lean for a second or two. It's normal as long as it doesn't last longer than a few seconds.
Old 02-24-2010, 10:34 AM
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Last month at our Corvette Club meeting we had some GM engineers talk about the LS9. They mentioned that E10 gas has a dramatic effect on their engine management calculations and that the E15 gas mandate is scheduled to start this summer. They have a new lookup table of Stoich vs % alcohol. So the PCM makes the adjustment on the fly to keep the supercharged engine from self destructing.

Perhaps its the E10 gas that is messing with your wideband readings?
Old 02-24-2010, 10:38 AM
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**** ethanol.
Old 02-24-2010, 11:04 AM
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This is why I tune using Lambda instead of AFR because these days with our ethanol blended BS fuels it makes the whole tuning process alot easier besides all widebands and oxygen sensors operate in the principle of Lambda not AFR, it just gets converted into units of AFR to be displayed on the gauge or controller. Much easier because a Lambda=1.00 is stoich for whatever fuel is in the tank whether its pure gasoline or 100% ethanol.
Old 02-24-2010, 01:15 PM
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Well let's say I have in second and not shift and let out high in the rpm band and let it slow it's self down. It goes way lean until the rpms get bak down around 3k or so?
Old 02-24-2010, 02:38 PM
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Originally Posted by black04silverado
Well let's say I have in second and not shift and let out high in the rpm band and let it slow it's self down. It goes way lean until the rpms get bak down around 3k or so?
yea prolly 20:1 or leaner..
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