99SH

I just picked up a gauge to start monitoring my IAT & water temps to get an understanding how ambient temp, oil temp and everything else plays together. I'm running the Novi 1200 w/the IAT sensor at the inlet of the blower. My air filter is at the bumper opening - so it's 'cold air'

What I'm noticing is that the IAT is roughly +15F relative to ambient. I'm also getting a sense that the IAT is really measuring under hood temps and not true intake air temp. While sitting in traffic, I can see my IAT rise to 91F while ambient is 71F.

How the heck does this sensor work if it's getting biased by heat-soak under hood temps?

redboost10

What type of sensors are they?

99SH

It's the stock IAT sensor, which I think is a RTD.

liquid_helix136

I've always battled a heat soaked IAT sensor when tuning my AP1. The IAT compensation tables are essentially useless imo, the sensor gets heat soaked at a stop light and reads hotter than the actual IATs unless the car gets moving for a few uninterrupted minutes. This was a big issue on AEM, and I would just run a summer map and a winter map to compensate. I'm now on Kpro and have run into the same problem, just not QUITE as big, but I still run a summer and winter map accordingly. The winter map typically just adds ~2% fuel to the overall trim, which typically puts things back to where they belong.

redboost10

honda iat sensor will get heat soaked from what i have seen...and on top of that it responds quite slowly.

s2000Junky

A couple things.

I tune to the stock sensor in the stock manifold location. This is the last place the air reaches before its hits the combustion chamber. The reason I feel that's the best location is purely for margins of safety since that also happens to be the hottest reading. But regardless of that, again that air is the last place before it hits the combustion chamber so its the logical reading to employ. I am pretty sure that was Hondas logic in putting it there as well.

As iat rises so does the higher chance of detonation. If your monitoring iat at the coolest location which would be just post aftercooler/pre tb(or filter location such as op ) and then using that information to set safety tune limits from, it will be inaccurate and usless. Also if your getting heat soak from under hood temps, then let the sensor reflect this, for stated reasons above. No sense in cherry picking here, that's not what the sensors job is.

s2000Junky

I don't know what your trying to learn here from making your iat sensor read the air temp going to your intake filter but your experimenting with a pretty crucial aspect to the cars engine function if you have that sensor manipulating your tune. If you wanted to read the outside temp just get a thermometer

99SH

Note, that on MY06+, the IAT is placed immediately before the filter not at the manifold like previous versions. Not sure what logic Honda used, but I agree with you to place it closest to the motor. The SOS kit also keeps the IAT at the filter location like Honda did (I believe out of convenience).


I don't agree. You want the ECM to receive the best & most accurate data possible to be able to determine the overall fuel trim & ign. If all the instrumentation feeding the ECM was over/under compensated by external factors, how can we expect the ECM to provide a reliable solution? Like I say at work, I'd rather have no data than bad data (and treat it as good). Give the ECM everything in its truest form, and leave it to use all the inputs and apply safety margins and what not in its resulting output. You don't want to 'calibrate' inputs, when it should be in raw form.

The sensor's job is to provide the intake temp, not intake temp + underhood temp.

RAIN H8R

The only way to get around a heat soaked temp sensor is to run no sensor, which is not an option. Or a custom sensor that uses water to keep the body cool would do the trick, but that is to German for my liking. Keep it simple is a good rule and dont worry about the heat soaked iat sensor Im not sure how 06+ sos kits are, but my opinion would be that it should mount between the throttle plate and aftercooler core. Keep things simple and leave it alone. Sent from my SCH-R970 using Tapatalk

SlowTeg

I have often wondered as well how accurate the IAT sensor is, but have always been too lazy to try and run some sort of test myself to verify the reading. My car is N/A, and putzing around in stop and go traffic I see +30-40F relative to ambient. When I start cruising for a bit on the highway the temps come down to usually somewhere around ~20F of ambient, but they can stay elevated for some time in stop and go traffic.

I have no doubt that the intake air temps are considerably higher than ambient in stop and go traffic (as the air is pulled from above the radiator w/ the stock airbox), but does the sensor itself get heatsoaked easily and have higher than actual readings due to being under the hood? Then I guess the question is whether the difference in actual vs. measured temps for the IAT sensor are "good enough" (say within 10F?)?