Tuning Methodology - Gen5 - IAT2/MAT - ZL1

[ls1x2]

I general terms, how do you treat MAT, IAT, and IAT2 when tuning these cars under boost? Specifically the ZL1 only references MAT for timing based on heat. AFAIK the math behind MAT has not been solved.

I've got my car (a10 '18 zl1) running quite well with some bolts ons and meth. Now, IAT2 LOOKS to me under the hood to be measuring what's in the intake like most cars today. IAT1 is in the cold air duct like most older cars. I never had any trouble accounting for that pulling timing for IAT/IAT2, etc.

My question is, would you just turn off MAT all together and tune based on IAT2 if you could, or do you see value in the MAT calculation that I don't see? My IAT2 stays right at ambient or drops 2* during a pull. MAT however increases. I DO see KR hear and there when the car gets good and heatsoaked "sometimes." ECT isn't much of a variable once in operating range from what I'm seeing in logs. Not clear.

[user_name]

107 reviews and 0 replies. If you've tuned a car like this you had to address it.

[eficalibrator]

The MAT model is designed to mimic the actual temperature of air entering the cylinders. The air picks up some heat from the intake ports after it has passed the IAT2 sensor, so this model accounts for that. Actual combustion characteristics follow THIS temperature, not necessarily the temperature up in the intake. The temp changes with cylinder head temp (which is slightly different from ECT), flow rate and time, just like a college level heat transfer class equation. The short answer is that if you have the stock heads and supercharger/intake/TMAP on it, this model is probably right.