Question on IAT tables for 2017 Camaro SS

So the other day while logging I noticed I wasnt seeing any changes to the tune from the IAT tables. I have a 17 Camaro SS 1LE with a Procharger D1SC that also has a Alky Controls meth injection system. I have the IAT plumbed into the intake manifold so when the meth injection sprays (using the meth inj only as a cooling effect, not for fueling) I can see the changes to the IAT values.

I noticed the scale on the IAT table stopped at 1.02 g/sec and at WOT I am seeing 1.40 g/sec. I also noticed the IAT table even though it was seeing 60* at WOT wasnt adding any timing even though it is commanded to add 1? starting at 68? and colder. I figured since the actual airflow was exceeding the scale for the table that is why the ECM wasnt adding any timing. I went into the IAT table and rescaled it to match the 2018 Camaro ZL1 tables. I ran another log and same results, still not getting any timing modification from the IAT table.

Is there any other tables that the scale may need to be changed on? Should I make sure all of the tables that use g/sec all match the ZL1's tables?

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Originally Posted by Sneakyws6

So the other day while logging I noticed I wasnt seeing any changes to the tune from the IAT tables. I have a 17 Camaro SS 1LE with a Procharger D1SC that also has a Alky Controls meth injection system. I have the IAT plumbed into the intake manifold so when the meth injection sprays (using the meth inj only as a cooling effect, not for fueling) I can see the changes to the IAT values.

I noticed the scale on the IAT table stopped at 1.02 g/sec and at WOT I am seeing 1.40 g/sec. I also noticed the IAT table even though it was seeing 60? at WOT wasnt adding any timing even though it is commanded to add 1? starting at 68? and colder. I figured since the actual airflow was exceeding the scale for the table that is why the ECM wasnt adding any timing. I went into the IAT table and rescaled it to match the 2018 Camaro ZL1 tables. I ran another log and same results, still not getting any timing modification from the IAT table.

Is there any other tables that the scale may need to be changed on? Should I make sure all of the tables that use g/sec all match the ZL1's tables?

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Pretty sure anything over 1.02 will use 1.02's values.

Log "IAT Advance" and see what it says you're getting from the table. Also, keep in mind that the numbers in that table have multipliers that affect them as well. IATxRPM, Coolant Temp, Humidity, and E content if you have a FLEX tune... all those things affect how much of the Base IAT values are applied.

I'm pretty sure on the LT1 that IAT is the immediate air temp at the MAF (or in your case your IAT sensor assuming you're using a MAF breakout cable) but, is not used by the ECU immediately. It slowly moves to this temperature based on the values of Bias and Filter tables under Cylinder Charge Temperature. If I log Manifold Temperature, it lines up with the IAT Timing adder table. There's 2 Manifold Temperatures able to be logged, one always displays 32F which is the wrong one. As an example, if I've been sitting in chick fil a drive through for 30 mins, both IAT and Manifold Temp get hot. Once I start driving IAT will come down reasonably fast and Manifold Temperature will slowly start to follow. You could try logging that and see if that more accurately reflects what you're seeing.

Is your IAT sensor that you added before or after the throttle body? If after, you could lower the Bias table while increasing the Filter table under Cylinder Charge Temperature to more accurately represent your IATs in your situation.

I have the IAT Advance logged, it sits at 0*. Once I get home later I will post up the tune and the log run.

I am using a 3 bar MAP, a MAP/IAT breakout harness as well. IAT is in the IM just past the TB.