after extensive insulation and thermal management experiments, the lowest i can get the IAT down to is 4*c while cruising - using the ambient sensor as the reference, which i know is slow and inaccurate at best.
While at most red lights, delta is usually around 10-13*c above but quickly recovers with vehicle movement.
This is with a Stillen G3 intake, wrapped in exhaust wrap, then wrapped in building sarking foil material, sarking foil over the power steering reservoir, and a sheet of sarking foil underneath the RHS/USDM passenger side intake pipe. The sheet underneath the pipe made a dramatic difference to stationary IAT temps, including situations such as short visits to the supermarket.
MAF cables are wrapped in exhaust wrap and sarking foil 4 inches up from the sensor flange.
I've also got huge ram air scoops which curve around the K&N filters so getting fresh, cool air is no issue.
FYI bank 1 = RHS/USDM passenger side.
Swapping maf sensors wont make a difference/cause any harm.
ECU only reads IAT from bank 1's sensor. I am unsure if the ecu will chuck a fit if you disconnect the IAT sensor (eg, cut the wires or de-pin them) from bank 2.
Since the IAT sensor is a thermistor, it's not 100% accurate by nature. Hence why the fsm for a lot of cars will show a table with two curves and a shaded area - ie the tolerance range.
You cannot calibrate a thermister, but you can program some compensation in some ecu's. Not sure if ours supports it - might be a question for uprev/ecutek. The principal is the same for using a non-OEM IAT sensor with a different resistance curve.
Our cars came with a lot of thermal management issues. Heatsoak is a major problem and really robs your enjoyment of the car. This problem is not helped by the narrow diameter of our intake pipes (and even the Stillen ones). Why? Because the IAT sensor is too close to the pipe wall, which radiates heat and affects IAT readings. If the pipes were of larger diameter, then the thermistor would be isolated further from the pipe walls and suffer less from radiant heat interference.
What's worse is there is a blazing hot metal coolant pipe running right underneath our intake manifolds. Not the black plastic thing, the metal toblerone manifold between it and the head! So no matter how well insulated your intake is, the air is going to get heated up right before it goes into the cylinder! I know the air velocity will keep the heat transfer to a minimum but every bit counts... and this heating is post-IAT so the ecu can't compensate for it.
So the 6*f high reading you get may not be much of an issue in reality, if we could measure the air temp right before the valves accurately you might be surprised.
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