Commercial mod: spoof intake air temp for more advanced timing

[izanti]

Hey all, I just bought this for my Dodge Ram truck. I dont know if any one else here actually owns a truck lol but it may be compatible with any chrysler vehicle. Its says only .5-1 MPG gain but I and many firends are getting up to 2MPG cause of our driving habits. Great investment!

http://airram.com/product.php?catego...6&productid=21

[Tourigjm]

I could probly get 5 mpg using painters tape

[MetroMPG]

This post was reported as being spam. I think it's the poster's style of writing (the original title, which I've edited, was: "Get an extra 2 MPG for only $50!!!") rather than actual spam, so I'm going to give him/her the benefit of the doubt.

FYI, the item being sold ("Power Wire") is probably a resistor that spoofs the IAT sensor (Intake Air Temp) signal to the computer to report cooler than actual temps. The result is said to be more advanced dynamic timing.

Question though: have you or many of your friends done any controlled A-B-A tests on this product to support the claims being made? Or are we looking strictly at less reliable tank-to-tank claims?

[izanti]

Hey all sorry this is caused some controversy. I wasn't trying to spam anything. if you want remove the link to the website. I just wanted to share this with everyone cause its helped me get an extra 3 gallons a tank.

Unfortunately we haven't tested this with a scan gauge or anything. just tank to tank testing. Hopefully I can get one soon and get the hard facts.

From what I have gathered its just like you said. It tricks the computer into thinking its colder outside so it runs a bit leaner. The thing I like about it is it just plugs right in so if anything does break as a result of this thing you can just unplug it and the dealership will never know.

Sorry for inconvenience of the title and hopefully someone else may save some gave with this thing.

[Red]

Its a cheapo resister that mods the IAT signal. Chrysler PCMs go into closed loop 30 seconds after start up so all this thing does is make the truck think its a little colder and richens up the mixture.

Are you driving any differently with it installed? An extra 3 gallons on a Ram is alot

[MetroMPG]

FYI, the link for this thing states the mod only affects timing, and air/fuel stays at stoich. I don't know if that's true or not.

[cfg83]

izanti -

Here is my take on the IAT-resistor-only mod :

1 - It "works" for performance WOT conditions because the ECU/PCM goes into open loop mode. Under open-loop mode, the ECU/PCM uses the IAT signal (as one of many input parameters) to determine fuel enrichment. The settings for performance will simulate CAI readings, aka lower input air temps.

2 - I claim it doesn't work under hypermiling driving conditions because the engine stays in closed-loop mode. In this situation, the IAT temperature reading to the ECU/PCM is ignored. As long as you don't stomp the accelerator pedal, it's not a factor.

On my Saturn, I have tested this with the ScanGauge by putting in different resistors and taking MPG readings over very short but multiple A-B-A test runs. The higher the "temperature spoof", the higher the MPG reading from the ScanGauge. However, the engine maintained exactly the same driveability.

CarloSW2

[nascarnation]

cfg83 - I agree 100%

the typical o2 sensor is a narrowband and can only "read" a few tenths either way of stoich
so if you're running in closed loop, you're very near or at stoich

the resistor mod will fool the scangauge and make it look like the mileage is higher but it isn't

[cfg83]

nascarnation -

Originally Posted by nascarnation

cfg83 - I agree 100%

the typical o2 sensor is a narrowband and can only "read" a few tenths either way of stoich
so if you're running in closed loop, you're very near or at stoich

the resistor mod will fool the scangauge and make it look like the mileage is higher but it isn't

Yup, that's what I observed (garbage in, garbage out). ... time passes while I search through crap ... Ok, I found the numbers I took down when I did the test last year. This was on a very short and almost-flat 1.5 mile run that I kept "round-tripping". You can see that the South MPG is higher because that is the downslope. The conditions were very stable for every run. This was before my 5th gear swap, so my cruise control still worked. In my opinion, CC on the (almost) flat reduces "the human right foot influence" during ABA testing. (EDIT: The CC MPH was set at 30 MPH) Here are the numbers :

July 5th, 2007 around 1 PM with an outdoor air temperature of around 90 degrees F :

Run 1 
Resistor simulating 200 degrees F (as reported by Scangauge) :
56.1 MPG North
57.6 MPG South (electric fan came on)
57.5 MPG North
57.07 MPG Average

Run 2 
Resistor simulating 247 degrees F (as reported by Scangauge) :
65.3 MPG South
59.8 MPG North
65.3 MPG South
61.3 MPG North
62.93 MPG Average

Run 3
Restored to "normal" Hot Air Intake with real IAT, 132 degrees F average :
57.7 MPG South
51.3 MPG North
57.7 MPG South
53.4 MPG North
55.03 MPG Average

As you can see, the numbers jump right out at you. The car drove exactly the same. No hesitation at higher MPG.

CarloSW2

[getnpsi]

You have to fool every sensor to make a difference, the most important one being the o2. You should look into moving the temp sensor to a colder area of the engine bay, or moving the air intake to a warmer area. that way your computer can still react in its specs and compensate without massive detonation/ping. I messed up and made a warm air intake and my old 1995 ecu couldnt change the timing enough so i had to go up to 91 octane until i changed more items.