Originally Posted by 84Laser
Does anyone know if 2012 cars are using this new long IAT sensor from the factory?
Originally Posted by BigDaddyWiz
If I had to venture a guess I would say yes. The 2011 charger intake tube that I ordered to replace my 2009 tube (that has a resonator) came with the longer temp sensor installed in it already.
Originally Posted by *********
My 2011 has the new long sensor
All 2011+ models that utilize the new airbox design have the new, longer IAT sensor. There have been no changes in the design between the 2011 and 2012 model year.
For $4, this is a very good modification to do and will work even better with relocating your sensor away from the throttle body as mikeychallenger did. The newer sensor is insulated better than the previous. Essentially, putting the sensor in the middle of the tube reduces the potential of the sensor reading intake tube sidewall temperatures rather than the actual intake temperature going through the tube.
Also to mention, this is not one of those "butt dyno I think I'm feeling more horsepower" modifications. You might not notice it as much in a 6-speed vehicle, but in the automatics, your transmission shifts during acceleration and deceleration are much smoother and less abrupt. Here is an example theory of what you can expect by doing this mod.
You're driving around town all day, you engine is already heatsoaked. You've been going in stop and go driving, you pull up to a stoplight and you have the following readings. Sensor is in the stock location.
- thread post reference for actual data
So the lag in acceleration in heatsoaked conditions is caused by sensor inaccuracy. This explains why we loose 20+ lbs/ft of torque in stop and go driving and why we get excessive engine knock and timing pulled in heatsoaked conditions after consecutive runs at the 1/4mi track. The air/fuel mix is leaned out because the PCM injects the improper amount of fuel for the actual air temperature entering the combustion chamber. As a point of reference, you'll get a lean air/fuel mixture if your sensor reads higher than actual air temperatures. This also results in the "spark trim", as Chrysler calls it, where the engine will use less spark advance to compensate for engine knock that resulted from an improper air/fuel mix. You'll also get a rich air/fuel mixture if your sensor reads lower than actual air temperatures. This results in the lag in acceleration from too much fuel. Notice how your peppyness of the Challenger is in cold vs hot weather.
Mikeychallenger showed us a few things.
- relocating the sensor away from heat sources allowed for a more accurate reading of the actual air flowing through the intake tube
- the difference in results showed that 20 lbs/ft torque is lossed
Some things that I have observed are
- as the engine heatsoaked, engine knock was detected as a result of an inefficient air/fuel mixture
- when the engine fans came on at idle, an unshrouded filter will heat up 10-20 degrees in temperature
I too verify the engine knock as I race down the 1/4mi track. I did 3 runs and the first run I had no engine knock. As I got to my 3rd run, I had engine knock detected on initial launch, and with every shift their after. My engine torque between the 1st run and the 3rd run was reduced roughly 20+ lbs/ft. The result was that I lost 2/10ths in the 1/4mi: same 60fts at 2.0x, 1st run: 12.7 @ 110, 3rd run 12.9 @ 108.
With this in mind, we increase sensor accuracy by moving it away from heat sources, which is exactly what the new sensor design does. We also increase sensor accuracy because the wire insulation on the new design is better than the old design.
I plan to do datalogging this weekend to see the difference between the two sensor readings to verify what mikeychallenger has pretty much proven with the relocation of the IAT sensor and how it reads more accurate.
The end goal is for the sensor to produce the most accurate actual air flowing through the tube temperature reading without reading the temperatures of the materials surrounding it.