Air Intake Information for GM's 3.6L V6

[scrming]

Originally Posted by David@Airaid

Hello CatiaJockey,

The Explanation would be that you are "Tricking" the computer into reading a cooler air intake temp, and that is going to cause issues with timing and can cause other problems down the road. The computer is also going to have to compensate for the improper reading.

The Airaid is already breathing cooler air and feeding the cooler air into the IAT sensor and it's getting a proper reading from that. The Inlet air is moving through that tube so fast that "Heat soak" is not really going to be an issue.

If a "Consumer" wants to do this mod, then that's up to them, however Airaid as a Manufacture does not recommend this modification.

Thanks,
David

Once again you don't seem to understand what I am saying.... The heat soak happens when YOU STOP AND PARK YOUR CAR (or get stuck idling in traffic) not while you are out driving around....

[scrming]

Originally Posted by David@Airaid

Hello CatiaJockey,

The Explanation would be that you are "Tricking" the computer into reading a cooler air intake temp, and that is going to cause issues with timing and can cause other problems down the road. The computer is also going to have to compensate for the improper reading.

The Airaid is already breathing cooler air and feeding the cooler air into the IAT sensor and it's getting a proper reading from that. The Inlet air is moving through that tube so fast that "Heat soak" is not really going to be an issue.

If a "Consumer" wants to do this mod, then that's up to them, however Airaid as a Manufacture does not recommend this modification.

Thanks,
David

Have you looked at the Jannetty Racing test results? They are here:

http://spreadsheets.google.com/pub?k...=1&output=html

You claim "The Airaid is already breathing cooler air and feeding the cooler air into the IAT sensor and it's getting a proper reading from that." The Janetty Racing test don't support that, in fact, it does just the OPPOSITE! The stock air box showed an increase of 4 degrees during the test while the Airaid showed an increase of 8 degrees!

Also you mention "improper readings". Looking again at the Jannetty results. The fuel trim went from -3% stock to +7% with the Airaid. Why? Is the MAF giving the "improper" reading? That's a 10% swing! And the fact is with my stand alone IAT sensor my long term fuel trims are BETTER than stock! My LTFT are in the +/-1.6% range!

[SNV]

I think what is trying to be pointed out is you are not getting a proper reading with the location of the IAT sensor. It doesn't matter if it's stock or with the CAI. It is being "tricked" with the wrong temp when heat soaked in the first place.

[CatiaJockey]

Originally Posted by SNV

I think what is trying to be pointed out is you are not getting a proper reading with the location of the IAT sensor. It doesn't matter if it's stock or with the CAI. It is being "tricked" with the wrong temp when heat soaked in the first place.

I disagree with this "tricked" statement. The new location is in the air stream, just at a closer point of entry than the stock location. If the air doesn't heat up during its journey down the tube then I say the closest point of entry is the better location because the IAT doesn't seem to absorb so much heat during idle or slow driving. I think scrming has a sound theroy and working model. David@Airaid only has presented one answer and that is calling it a trick.... I'm calling this BS until an engineer comes in with "technical" reasoning.

[CAI Inc]

Originally Posted by David@Airaid

Hello CatiaJockey,

The Explanation would be that you are "Tricking" the computer into reading a cooler air intake temp, and that is going to cause issues with timing and can cause other problems down the road. The computer is also going to have to compensate for the improper reading.

The Airaid is already breathing cooler air and feeding the cooler air into the IAT sensor and it's getting a proper reading from that. The Inlet air is moving through that tube so fast that "Heat soak" is not really going to be an issue.

If a "Consumer" wants to do this mod, then that's up to them, however Airaid as a Manufacture does not recommend this modification.

Thanks,
David

I have to agree with David on this one.

[Xanthos]

I'm with scrming. The evidence seems pretty clear that the stock IAT sensor gets too hot because its right next to the MAF sensor. From an engineering stand point - and a lot of my undergrad work has been in engineering - moving it to a location seperate from the MAF sensor but still inside the intake system would not be "tricking the system." IAT sensors are not like MAF sensors that have to be calibrated for position - they simply read a temperature. We use very similar sensors in our data centers here at OU to monitor the intake/exhaust temperatures on our servers.

Now, moving the sensor to a location outside of the intake - or using a resistor to modify the output signal - would be "tricking" the sensor.

Just calling it how I see it. Take it as you will.
- X

[scrming]

Originally Posted by CAI Inc

I have to agree with David on this one.

That makes sense with the Cold Air Inductions system... You guys use a nice ceramic coated tube!

[scrming]

Originally Posted by CAI Inc

I have to agree with David on this one.

Hey... Lapeer is open to the end of November... We could bolt one of your prototypes in my car and make some passes!!! LOL!

[CatiaJockey]

Originally Posted by CAI Inc

I have to agree with David on this one.

Care to give a detailed technical explanation....

[SNV]

Originally Posted by CatiaJockey

I disagree with this "tricked" statement. The new location is in the air stream, just at a closer point of entry than the stock location. If the air doesn't heat up during its journey down the tube then I say the closest point of entry is the better location because the IAT doesn't seem to absorb so much heat during idle or slow driving. I think scrming has a sound theroy and working model. David@Airaid only has presented one answer and that is calling it a trick.... I'm calling this BS until an engineer comes in with "technical" reasoning.

Think I might have come across wrong. I do agree with what scrming has said. I only used the word "tricked" because it is being tossed around lol. I think relocating it is a good idea.

[14pilot]

Disagree with the term "Tricked". The relocated IAT sensor is reading actual Intake Air Temperature at the filter box. This is a more realistic reading than the stock MAF/IAT that sits right over the radiator exit hose. The stock MAF/IAT is an engineering compromise for reducing the cost of divorced MAF and IAT sensors. Separating the IAT from the MAF is valid for performance. No trick, just common sense. I did this mod on my LS1 truck nine years ago, 100K hard miles - zero issues. Older F-bodies and corvettes came with divorced MAF and IAT sensors for many years of production. Just 'cause GM found a cheaper way to put the MAF and IAT sensors together doesn't mean that this this the best way to do it.

[kga10734]

Originally Posted by 14pilot

Disagree with the term "Tricked". The relocated IAT sensor is reading actual Intake Air Temperature at the filter box. This is a more realistic reading than the stock MAF/IAT that sits right over the radiator exit hose. The stock MAF/IAT is an engineering compromise for reducing the cost of divorced MAF and IAT sensors. Separating the IAT from the MAF is valid for performance. No trick, just common sense. I did this mod on my LS1 truck nine years ago, 100K hard miles - zero issues. Older F-bodies and corvettes came with divorced MAF and IAT sensors for many years of production. Just 'cause GM found a cheaper way to put the MAF and IAT sensors together doesn't mean that this this the best way to do it.

I agree with this.

Here is my take on the relocation of the sensor, please try to follow me I don't know if I can explain it as well as I'm thinking it....

I put the relocated sensor just outside of the air filter inside the air box. It is reading the temps of the air that is going into the filter instead of the air temps that are coming through the filter like the stock IAT sensor, which the air temps should be the same on both sides of the filter. I don't think that the air would heat up just by passing through the filter. So I am not "tricking" the computer to think it's getting colder air then it is. This is giving the computer a more accurate reading of the air temps going into the engine.

The problem is that the air tube(stock or after market) is heating up and that same heat is dissipating into the the MAF/IAT sensors which is causing the heat soak. Yes if you drive around a while the temps will drop down a bit but not enough to give you an accurate air temp reading because the air tube and stock sensor are heated up more then the air going through it.

Here is a test you can do. Before you drive the car anywhere, pop the hood and see how cool the engine cover, intake tube, and air box are before you start it up. Doesn't matter stock or aftermarket, they should both be somewhat cool to the touch. Now go drive down the road a few miles and come back. Pop the hood and you can feel the heat coming off the engine bay. Put your hand on the engine cover, intake tube and the far right hand side of the air box and tell me which is the coolest of the three. Close the hood and go back in about 20 - 30 minutes and check it again. Odds are the engine cover and intake tube are even hotter now because the heat from the engine has dissipated to the engine cover and down the intake tube toward the air box. This is what is cause the heat soak and the MAF/IAT to read hotter temps then the air going through the intake tube. With the relocated IAT sensor you should be able to get in the car and it will respond just like you started it up first thing in the morning, because the sensor itself isn't hot so it is reading the air temps going through the air filter, down the intake tube and into the cylinders.

[CatiaJockey]

Originally Posted by SNV

Think I might have come across wrong. I do agree with what scrming has said. I only used the word "tricked" because it is being tossed around lol. I think relocating it is a good idea.

I took it that you were just explaining something that was stated, not defending the position.... I'm disagreeing with David@Airaid's explanation. Personally I think the relocation of the IAT on a stock system is more bang for the buck than a CAI and the vendors are trying to steer us away from that fact.

[CAI Inc]

Originally Posted by CatiaJockey

I took it that you were just explaining something that was stated, not defending the position.... I'm disagreeing with David@Airaid's explanation. Personally I think the relocation of the IAT on a stock system is more bang for the buck than a CAI and the vendors are trying to steer us away from that fact.

You want the most accurate reading possible. The best place for an IAT sensor is in the upper intake manifold. This gives the most accurate readings. The further you move it down stream will tell the computer the IAT are lower then what they really are. I can get more in depth but I'm writing this from my phone.