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I quote from March 2006 AIM - Donny Peterson's Techline " The factory mechanic recommended and I heartily agree, installing a second air temperature sensor in the back of the air cleaner mounting assembly. Locate it so that the temperature sensing probe is inside the confines of the air cleaner element. Unplug the lead from the stock location air temperature sensor and plug it into the newly installed sensor inside the air cleaner element. Leave the stock sensor in place, as it's new function is to plug a hole. The new sensor will now send back cooler signals to the computer, which in turn, dictate permission for the fuel mixture to be richer. This equates to cooler, which will at least lessen, and maybe eliminate the pinging.

Does this hold water? Would it be a good fix for light pinging in the Summertime? I'm hoping HDWRENCH, Grock and others on top of the fuel injection curve will shed some light on this subject. For example, if my bike is tuned about as far as it's going to go and I'm pinging under load, would doing this fix the problem without having to pull some timing out of one or both of the cylinders?

Thanks for the info guys.
rpb
 

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I think it would deliver more fuel

If the ecm thinks the temp of the air in the manifold is cooler it will calculate a higher density for the air which will result in more fuel.(the efi is a speed-density system)
 

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Hellbound Train
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1. Why would you assume the air is cooler inside the A/C?
2. If it is, how do you know the ECM is not already compensating for the difference?
 

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csoday said:
1. Why would you assume the air is cooler inside the A/C?
It's farther away from the engine, kind of makes sense it would be cooler than right between the cylinders.
 

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The ECM may be compensating for a difference...but it has to have an initial reading to compensate from. Since it's only air temp reading is at the intake...lowering this value by sticking the sensor in some colder air should result in a fatter mixture. Hey...why not just tune it correctly.... Or if you have a SERT and want an even easier way to richen eveything up..top to bottom..side to side....go into set up and add a few cubic inches displacement.
 

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csoday said:
1. Why would you assume the air is cooler inside the A/C?
2. If it is, how do you know the ECM is not already compensating for the difference?

I don't think the ECM is supposed to compensate. The way I read this is that it's a "trick" intended to fool the ECM. It does make sense that a sensor placed further from the heat of the engine would be a few degrees cooler. A lower temperature reading at the sensor would result in the ECM deciding to richen up the mixture. It's a shame that such a workaround would be necessary, but in theory it seems as though it would work.
 

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IronButt
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In a t/b or intake manifold with increase velocity you will see a cooling effect, infact a a trick used on 5.0 and tpi motors on cars was to remove the bypass cooler line from the t/b to get a cooler air charge into the engine, the downside was at lower temps in the low 50's and high humidity you could get the throttle plate to freeze. I had a chart that showed a chart with amount of flow verse's temps the amount of cooling effect you would get. But I think it would be a wiser choice to tune it correctly
 
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