Air Intake Information for GM's 3.6L V6

[dagolfguy]

People are really saying the same thing. Let's break it down:

I believe everyone can agree with the statement that we want to give the PCM the most accurate information about the tempurature of the air coming into the engine. Nobody is suggesting that we attempt to trick the system by providing the opportunity for a false reading.

What is in dispute is the best way to provide that accurate reading.

Those who believe that relocating the IAT is a good idea, feel that the sensor itself is reading hot because the parts around it are getting hot and therefore the sensor is providing the system a false reading. Those who believe we should leave the sensor alone believe that the air entering the engine is warmed by the components it passes through, and that reading the temp upstream provides a false reading of the air temp that actually enters the combustion chamber.

Summary-
We all believe that an accurate air temp reading is what we strive for. So, the question is this:
What is better and what is worse:
If the IAT is installed in a place where it gets hot from the engine and provides a too warm air reading or if the IAT is providing a reading of temp before the air is warmed from passing through the intake components?

[scrming]

From the Vector Motorsports website: (http://www.vectormotorsports.com)

"Testing has shown that once the MAF sensor housing becomes heatsoaked your intake air temperature (IAT) sensor can read up to 50 degrees hotter than the actual temperature of the air being injested by the engine."

Also I was talking with Lidio from Alternative Auto during his dyno day and we got talking about my "divorced" IAT sensor... he said his G8 suffered terribly from this heat soak issue and that he noticed that by the time he actually got his G8 staged his IAT temps were reading a 160 degrees! So he asked me for the part numbers for this mod so he could do this on his G8, which he did...

[devildoc]

scrming - have noticed any changes in gas mileage yet?? and for the fact that you have had this mod done for at least a month now that you have noticed no negative issues correct?

[scrming]

Originally Posted by dagolfguy

People are really saying the same thing. Let's break it down:

I believe everyone can agree with the statement that we want to give the PCM the most accurate information about the tempurature of the air coming into the engine. Nobody is suggesting that we attempt to trick the system by providing the opportunity for a false reading.

What is in dispute is the best way to provide that accurate reading.

Those who believe that relocating the IAT is a good idea, feel that the sensor itself is reading hot because the parts around it are getting hot and therefore the sensor is providing the system a false reading. Those who believe we should leave the sensor alone believe that the air entering the engine is warmed by the components it passes through, and that reading the temp upstream provides a false reading of the air temp that actually enters the combustion chamber.

Summary-
We all believe that an accurate air temp reading is what we strive for. So, the question is this:
What is better and what is worse:
If the IAT is installed in a place where it gets hot from the engine and provides a too warm air reading or if the IAT is providing a reading of temp before the air is warmed from passing through the intake components?

Exactly!

When the car is cold and you take it out for a drive the stock IAT sensor will provide accurate air temps. The issue I have is once you stop and park it! That's when the MAF/IAT sensor becomes heat soaked (as shown in my video). And once the MAF is heat soaked, it appears that the stock IAT sensor is reading the heat from the MAF housing, NOT the actual air! Eventually the MAF sensor will cool off and the IAT can start reading the air temp again. But my testing has shown:

A) At highway speeds (75 MPH) it can take up to 3 or 4 miles for the IAT to come back down to a reasonable temp.

B) Around town doing 35 MPH is can take 5 to 7 miles for the temps to come down

C) In stop and go traffic the temps may never come down.

Ok... as for which is better to hot or to cold...

1) Too hot - ECU pulls timing. We know the ECU starts pulling timing at like 86 or 88 degrees.

2) Too Cold - ECU adds timing. My observations is 3 to 5 degrees. But the ECU is also going to add some fuel which should help prevent any detonation from the extra timing. Also I've been watching my long term fuel trims under varying driving conditions. They are staying +/-3% range but most of the time they are in the -1.6 to -.8% range...

Ok... I feel I've have provided enough explanation and supporting evidence that at this point I'm

[scrming]

Originally Posted by devildoc

scrming - have noticed any changes in gas mileage yet?? and for the fact that you have had this mod done for at least a month now that you have noticed no negative issues correct?

MPG may have gone down very slightly... really hard to tell as it seems my right foot has gotten a lot heavier since this mod! LOL! The other day I did set the cruise at 58 MPH and was still getting 30 to 31 MPG...

No negative effects... as a precaution I was running premium for the first couple of tanks of gas but have now been running 87 for the last 5 of 6 tanks of gas... Also I've made about a dozen passes at the track...

[CAI Inc]

Originally Posted by dagolfguy

People are really saying the same thing. Let's break it down:

I believe everyone can agree with the statement that we want to give the PCM the most accurate information about the tempurature of the air coming into the engine. Nobody is suggesting that we attempt to trick the system by providing the opportunity for a false reading.

What is in dispute is the best way to provide that accurate reading.

Those who believe that relocating the IAT is a good idea, feel that the sensor itself is reading hot because the parts around it are getting hot and therefore the sensor is providing the system a false reading. Those who believe we should leave the sensor alone believe that the air entering the engine is warmed by the components it passes through, and that reading the temp upstream provides a false reading of the air temp that actually enters the combustion chamber.

Summary-
We all believe that an accurate air temp reading is what we strive for. So, the question is this:
What is better and what is worse:
If the IAT is installed in a place where it gets hot from the engine and provides a too warm air reading or if the IAT is providing a reading of temp before the air is warmed from passing through the intake components?

If this is true why does this not happen when you install one of our intake systems? All you have to do is sample the IAT's at 4 different locations at the same time.

[scrming]

Originally Posted by CAI Inc

If this is true why does this not happen when you install one of our intake systems? All you have to do is sample the IAT's at 4 different locations at the same time.

As I pointed out... your tube is has a ceramic coating, correct? Would be interesting to do the 20 minute parking test and see if the stock MAF sensor becomes heat soaked...

And of course how do we KNOW that this doesn't happen with your system since the V6 version isn't available yet? LOL!

[SNV]

Originally Posted by CAI Inc

If this is true why does this not happen when you install one of our intake systems? All you have to do is sample the IAT's at 4 different locations at the same time.

Have there been tests done to see if it gets heat soaked on your intake?

[CAI Inc]

Originally Posted by scrming

As I pointed out... your tube is has a ceramic coating, correct? Would be interesting to do the 20 minute parking test and see if the stock MAF sensor becomes heat soaked...

And of course how do we KNOW that this doesn't happen with your system since the V6 version isn't available yet? LOL!

It doesn't happen with any of our systems. If heat soak caused this it would happen with our system also. If you touch our ceramic tube it will be hot on the out side. The sensor will still heat up through conduction. One more thing to consider, anytime air changes direction it heats up.

[CAI Inc]

Originally Posted by SNV

Have there been tests done to see if it gets heat soaked on your intake?

We test all of our systems. Here is one example

[SNV]

Originally Posted by CAI Inc

We test all of our systems. Here is one example

I have seen your pics of the v8 cia. I have not seen pics for the v6. Did you leave the sensor in the same location or move it closer to the box?

[CAI Inc]

Originally Posted by SNV

I have seen your pics of the v8 cia. I have not seen pics for the v6. Did you leave the sensor in the same location or move it closer to the box?

We try to keep the sensor 4-6" from the filter pleating.

[SNV]

So in a way you did relocate it correct?

[CAI Inc]

Originally Posted by SNV

So in a way you did relocate it correct?

Yes, in the opposite direction you guys are moving it.