Hey guys. Currently working on a boosted d16 build and am playing around with the idea of making a custom engine harness which will give me the ability to pick placement for sensors like IAT.

What I want to know is will I really see a difference if I place the sensor in the charge piping, will it be biased in any way? I'm currently using a s2 pro intake mani w/ stock tb, and the IAT is on the first runner,going in through the side. It's not exactly ideal placement and it was actually threaded when I got it (dilled out slightly to accept factory IAT sensor) so I want to put a block off plate on it and relocate the sensor.

Is there any benefit to it or will it actually throw the tune off? Can it be emulated/compensated for in the tune?I may or may not run the hondata heat shield sensor as well. I'll have to research that first.

 

You have to run an IAT sensor, the ecu won't be able to function properly without it.

the biggest issue is heat soak, the sensor body itself absorbs heat. the other issue is the stock sensors are closed junction so they respond very very slow. I modify them to open junction types and response goes from a few seconds down to a fee milliseconds.

As long as it measures the air temp entering the motor (cold charge pipe or intake manifold) then its position doesn't really matter

 

What is this open junction that you speak of?

 

What he is trying to say is the stock ones are covered with plastic. He removes the plastic covering the thermo resistor for a faster response time. The manifold location will in fact heat soak the sensor. It has been proven. Most prefer to put them at most 6-8" in front of the throttle body.

 

So is it better to move the sensor and throw off the reading a small bit, or to leave it in the stock location and use something like the hondata heat shield to ACTUALLY lower intake temps and reduce heat soak to the intake manifold?

 

The heat reduction is minimal, you still have hot air flowing through the manifold and the bolts and studs still transfer heat into the manifold. that being said the gasket does reduce heat transfer to the manifold

the stock IAT sensor junction is coated in a silicone like substance then a black layer of rubber followed by a gray layer. the real issue is once the sensor is heatsoaked it no longer accurately or efficiently measures changes in air temperature. it takes a while for those layers to shed the heat they absorb.

you can modify yours to open junction with a sharp razor and a steady hand but be forewarned that the stock thermocouple is very fragile, I broke 2 sensors before perfecting the method. I've also done it to GM IATs with good results, however I have not datalogged the changes. anyone who does this will immediately see the difference when logging.

 

I've seen a lot of people talk about using the GM IAT sensor. Are there any benefits to that? Or is it more trouble than it's worth to calibrate and such?

 

I don't see how that can be of any advantage to anything. What specifically were you seeing people discussing about?

 

https://honda-tech.com/forums/forced-induction-16/anyone-use-gm-iat-sensor-2141968/

There's one example of it, albeit an old old thread. I remember coming across something talking about the GM IAT sensors when I was doing some digging on WantBoost's open junction comment last night. People saying they couldn't be used.

 

It is an exposed junction is why. An obvious advantage over a closed junction, but the range is different than Honda's. Plus the GMs are already threaded. An easy solution to that is to use the CRV's threaded IAT sensor.

 

The problem with the GM sensor is that is has a different voltage scalar table, so it wont work well with a stock ecu. the temp the ecu reads will be wrong because of this

most setups using a GM IAT sensor are running true standalones and not using a Honda based ecu

it's also worth mentioning that some GM IATs are open or closed junction. I've seen the same threaded sensor come both ways.

 

When you say "stock ecu" are you referring to an un-chipped OEM ecu? Or are you speaking about all OEM-type ecu's, chipped or not (as opposed to a standalone)? Can it be calibrated to scale via tuning software?

 

Honda based ecus, not really. chipped or not