I have logged a dozen or so runs with Osiris Tuner version and noticed that intake air temperature will always read higher than the ambient air temperature.

To be specific, in the case of cold starts after 10 to 12 hours sitting overnight (no heatsoak) the intake air temperature measured by Cipher or Rom editor is always 8 to 12F degrees higher than the ambient air temperature.

Why is this? Can anyone explain?

Is this normal for a stock 03 G35 coupe MAF/IAT sensor or is the stock MAF/IAT not designed for great accuracy?

Is my MAF/IAT malfunctioning but not throwing codes? The FSM is silent on temperature readings, referring only to a IAT too low or IAT too high code.

Other forums members from corvette, mustang say that IAT senor readings are only a few degrees F above ambient (few meaning 3 degrees or less).

Can MAF/IAT be recalibrated in Osiris Tuner?

Does 8 to 12F degrees above ambient air temperature make much difference to the ECU when timing?

Since there is no heatsoak, is the additional 8 to 12F degrees designed to help cold starts?

 

manufacturing tolerances plus as soon as you start the engine heat will be generated and pulled in. especially if pulling in from the engine pay or near it.

 

^^^

+1

My intake temp is within 2-4 to ambient air temperature....intake mainfold/intake runner/long tube injen painted with high temp along with being wrapped. During the day it's pretty close, at night it's dead on while cruising.

 

Thanks for the reply guys. I should also mention that I have a JWT pop charger with a custom sealed Stillen air box, z-tube. Everything is thermal wrapped (air box, MAF housing, tubing etc). I also cut a 3.5" hole in the radiator core support with custom tubing behind the front grill, similar to the 350z design.

Actual my Intake air temperature sensor readings in cipher where 30 to 50*F above ambient air temp prior to all the custom mods. I took great deal of time and effort making one change at a time (modding, testing, analyzing, sometimes unmodding, retesting) to get the IATs down to 8 to 12*F above ambient.

I seem to have hit a wall. If you are right KingBaby, I should be able to get to 2 to 4*F above ambient. But I'm fresh out of ideas at this point.

Thanks.