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Does ECU pull timing in Open Loop like it does in Closed Loop?

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Old Jul 1, 2015 | 06:07 AM
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Default Does ECU pull timing in Open Loop like it does in Closed Loop?

I relocated my AIT sensor from stock manifold location to the Pre-Throttle Body location on the after-cooler and my temps don't break 100f where before in traffic they would be between 135f to 165f.

Driving in the 90f summer humid heat even with a passenger and AC on is now a joy. It is no longer a dog and doesn't feel like crap in traffic. She doesn't bog.

My understanding is that before my stock ECU with E-Manage Ultimate would pull timing above 110f, now it doesn't. Now as I bang though gears and get into 10+psi boost, temps skyrocket to 123-130f and drop as boost decreases. Does ECU start pulling timing in OPEN LOOP under WOT as I cross 110F in higher boost during these pulls? Or does stock ecu only pull timing in Closed Loop?
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Old Jul 1, 2015 | 08:08 PM
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On stock ECU, the only thing unique to closed loop operation is that it will trim the fuel injector pulsewidth to fine tune air/fuel ratio. But it only goes into closed loop mode during very strict conditions, like idling. So that's why it only needs a narrow band EGO. All other functions, like IAT temperature correction, are in effect even during open loop.
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Old Jul 1, 2015 | 09:30 PM
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Open loop transition starts right about 35% throttle on the 01 ecu. I would bet its the same from 00-05. Not sure about DBW 06+
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Old Jul 1, 2015 | 10:17 PM
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I've been considering doing this as well (moving iat sensor). I'm running aem v2. Would I need a retune?
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Old Jul 2, 2015 | 05:43 AM
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Shouldn't need a retune, but what are you expecting it to do for you if you are running AEM? If your map is not utilizing any air temp trims then there will be absolutely no change, other than your IAT numbers not spiking at idle and cruising. I've got an ignition trim starting at 140*, but I only see those temps while idling for a long time in traffic because the sensor gets heat soaked. As soon as I start moving the temp drops right away.
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Old Jul 2, 2015 | 06:10 AM
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Originally Posted by tom153
Shouldn't need a retune, but what are you expecting it to do for you if you are running AEM? If your map is not utilizing any air temp trims then there will be absolutely no change, other than your IAT numbers not spiking at idle and cruising. I've got an ignition trim starting at 140*, but I only see those temps while idling for a long time in traffic because the sensor gets heat soaked. As soon as I start moving the temp drops right away.
I am so doing this and so excited, Houston traffic and my long commute sucks in the summer time.
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Old Jul 2, 2015 | 07:18 AM
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All I can say is, it is a night and day difference in part throttle and around the city without ECU pulling timing and going Full Retard on me.
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Old Jul 2, 2015 | 07:28 AM
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Yea, for those of you guys who are running OEM ecu or piggy backs I can see how it can make a difference; the reason I said that to Habitforming was because he's running AEM V2. If your map is not using any aggressive IAT trims then there's no need to waste time moving the sensor for zero gains...
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Old Jul 2, 2015 | 07:30 AM
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The original location is giving an inaccurate reading is the case?
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Old Jul 2, 2015 | 09:56 AM
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Originally Posted by tom153
Yea, for those of you guys who are running OEM ecu or piggy backs I can see how it can make a difference; the reason I said that to Habitforming was because he's running AEM V2. If your map is not using any aggressive IAT trims then there's no need to waste time moving the sensor for zero gains...
I appreciate the heads up. I figured any engine management / tune would have some compensation built in for IAT, but I guess that was a poor assumption. I'll have to have a look at my tune and see if he has anything in there for it.
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