Air Intake Information for GM's 3.6L V6

[CAI Inc]

Originally Posted by transfrmn

CAI Inc. question for you do you recommended the fuses be pulled to reset the ECM when your intake is installed? I emailed you a bunch of question on the website i might order from you soon but i forgot that one lol

Ether way will work.

[scrming]

Originally Posted by transfrmn

i understand what your saying too and what their saying, i would rather get a CAI that moves the thing inside of the heat shield as i do not like voiding my warranty. But for curiosity's sake is it possible GM knows about heat soak and is having their computers already adjust for it. I know your car runs faster when its been moved because its a better position but could that reason be because your car is now overcompensating which could cause problems in the future

As pointed out by 14pilot (http://www.camaro5.com/forums/showpo...6&postcount=53) guys having been doing this to their f-bodies, corvettes, G8s, Trailblazers, etc. for a long time... There are companies like Vector Motorsports that sell "relocation kits"...

Also, don't know how GM could adjust for the heat soak... how can you tell the difference between a heat soaked MAF and just plain hot air?

[scrming]

Originally Posted by transfrmn

i understand what your saying too and what their saying, i would rather get a CAI that moves the thing inside of the heat shield as i do not like voiding my warranty. But for curiosity's sake is it possible GM knows about heat soak and is having their computers already adjust for it. I know your car runs faster when its been moved because its a better position but could that reason be because your car is now overcompensating which could cause problems in the future

Also... remember, there are checks an balances in the system. For example the fuel trims and the knock sensors. These things are in place to "correct" things in case one of the sensors, whether it's the IAT or the MAF sensor, starts feeding the ECU incorrect data... The data coming in from these sensors is only so accurate... I think this is especially true if you start looking at things like the fuel trims which is really just a way for the the ECU "fine tune" things to get the correct Air/Fuel ratio.

Lets say I am over compensating and feeding the ECU an IAT temp that was way to low. In theory the ECU should say, "Oh, COLD air = denser air = more oxygen = more fuel" Now unfortunately I never paid attention to the long term Fuel Trims before this little experiment, but I see the stock SS from the Jannetty test was running -3%.... Anyways, I've been watching the long term fuel trims and they basically are running between -0.8% and -1.6% with an occasional -3.1%. Some times I'll set +0.8% or +1.6%... but basically this tell me that overall the ECU is do a pretty good job calculating the proper fuel amounts based on the relocated IAT...

Again... i'm happy and comfortable with this mod... but I will re-state... do at your own risk, YMMV, etc...

[MontyCarlo]

How much thermal mass could the MAF housing really have?

[Beauwulf]

Airaid intake ordered! I look forward to reviewing this mod!

[Beauwulf]

Originally Posted by David@Airaid

The new Camaro direct injection system is advanced. The PCM is capable of identifying sensor readings that are outside of acceptable parameters and will compensate. The ability to compensate for sensor readings will allow the PCM to function with what is assumed to be degrading components. Sensor readings such as Mass Air Sensor frequency are expected to be within a particular range when sampled along with other engine sensors readings to include engine RPM, throttle position, etc. A component or group of components that cause sensor reading to be outside of acceptable range will lead to compensation settings from the PCM. The malfunction indicator lamp can illuminate if sensor readings (or combination of readings) are beyond these acceptable limits.

The PCMs ability to compensate results in restored functionality (or loss of temporary performance gains). Vehicle modifications can result in temporary “improvements” that are later adjusted back to original performance if those modifications result in sensor readings that are outside of the expected parameters. For example, installing an intake system with less restriction (more air flow) and mass air sensor mounting location that does not allow for proper sampling of the additional air flow. This will force the PCM to make necessary adjustments until it receives acceptable readings or combination of sensor readings. These “adjustments” result in original performance levels or an illuminated MIL if requirements are met.

An intake system that is properly designed to provide less restriction (more air flow) while allowing the mass air sensor to sample the incoming air flow accurately (as it did in the original intake) should not result in the PCM re-learning or compensating. The additional air flow resulting from less restriction should be measured from the mass air sensor accurately as the correct frequency reading per volume of air. Additional air flow should continue to be sampled accurately from the mass air sensor until the additional amount of air flow exceeds the functional limits of the mass air sensor or the allowable parameters of the PCM.

An unmodified Camaro will perform better at sea level than it will at 7000 feet elevation. This is due to the more dense air that is available at sea level. The mass air sensor will accurately read the difference in air density and the PCM will process accordingly (not relearn the performance back out) because the other PCM readings and functionality are within allowable limits. A properly modified Camaro will respond the same with additional air flow being measured accurately while maintaining sensor readings that are accurate and within allowable spec of the PCM.

The challenge for aftermarket manufacturers is to develop performance systems that provide added air flow while retaining sensor functionality within their design limits. Our staff of engineers and ASE certified techs utilize our in-house chassis dyno, flow bench, mass air sensor flow bench, rapid prototype equipment and much more to insure our products function and fit as intended. Our success has resulted in the consultation of performance intake systems to OEM manufacturers.

I would just add one bit of info to this... The design perimeters for the PCM should be calibrated to function at any elevation the equipment might encounter in normal use. In the US, that would cover a range of operation from 283 ft below sea level (Death Valley) to the highest point on US 34 in the Rockies (12,283 ft). The road up Pikes Peak is close to 14K and cars still function there (albait at a much reduced HP) all the time....

There will also be some consideration for thermal variances at these locations. Density altitude (DA) is what the PCM actually uses to adjust the mixture with. It is a calculation of pressure altitude (PA) and air temperture. So a modification that changes DA, and is still within those parameters, will not throw a code (CEL). As you can see, there is a fairly large amount of variance within this calibration.

Density Altitude is just an attempt to account for non-standard pressures and temperatures. Pressure altitude adjusted for non-stand temperatures gives us Density Altitude. Density altitude and temperature work in the same direction; lower temps, lower density altitude, higher temps higher density altitude.

On a side bar... this is where SCRMIN's IAT relocation comes in to the picture. DA is a calculation of PA (pressure altitude) and inlet temps. If either of these are incorrect, it multiplies the error in the fueling. Sampling rates of the O2 sensor are fairly quick for adjustments but if your not getting the correct temp reading into the PCM, your leaving HP on the table!

Simply put, you can increase airflow (and fuel) up to the point where it matches the maximum DA at Death Valley in winter (say.. somewhere in the -500 ft range) and the PCM has enough range to compensate for it. On the other end of the spectrum, your car will still run on top of Pikes Peak in the summer. This is a pretty good engine control system we have these days!

[datelgemeier]

Question. Is the stock IAT heatsoaking because it is coupled with the MAF sensor? If this is the case could the divorced IAT be mounted near the existing MAF/IAT sensor and not heatsoak? Or is it heatsoaking because of where the original sensor is mounted?

Thanks,
Duane

[Xanthos]

Originally Posted by datelgemeier

Question. Is the stock IAT heatsoaking because it is coupled with the MAF sensor? If this is the case could the divorced IAT be mounted near the existing MAF/IAT sensor and not heatsoak? Or is it heatsoaking because of where the original sensor is mounted?

Thanks,
Duane

Its because its coupled with the MAF sensor (which gets quite hot) - moving it to a location nearby *should* fix it as well.
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