From what ive read:
It works by fooling your ECU into thinking that the air coming into the intake is colder therefore causing it to advance the timing and letting out the fuel supply creating more horsepower.
I was thinking of buying one of these and was wondering, would this decrease your gas milage? (I do own a v6 but no one has responded to me when I posted this so maybe you can help)

 

Nobody answered because it is obvious-- more horsepower is derived from more fuel/air; you increase horsepower you have to increase combustion.

 

I don't think his question was obvious, nor did your answer Bring his question any closer to resolution.

If what your research is saying is that the the motor will be slightly leaned out, meaning a little more air will be delivered in respect to fuel, then yes, you may see a slight increase in your mileage.

Anyone else like to chime in with first hand experience?

 

In actuality it is TRICKING the car into thinking there is more air; therefore more fuel will be introduced since the same amount of air is entering. The temp trick only means it is thinking the air is colder so it introduces more timing and as the pcm's logic is concerned more fuel for colder air.

 

What it tells the PCM depends on whether you are talking a mass-air system, or a speed-density system. I really have no idea what they use in the V6, but I suspect it is mass-air. In that case and assuming the setup is similar to the LT1, the IAT is only used for a minor timing offset, primarily some retard (3deg???) at high inlet air temps. The mass-air meter takes care of telling the PCM how much air is flowing into the engine.

 

those resistors make the car run LEANER. Less fuel = more hp and better gas milage. Definately not the best thing for your engine tho. Getting your pcm professionally tuned will do the same thing but without the risk of running too lean or detonating

 

theory is that when our cars are first started they are considered "cold" so fuel is increased like the method for using a choke on older vehicles. Once vehicle gets to operating temperature "hot" it leans the mixture. If you are telling your car it is cold out what do you think the pcm is going to do? Increase the fuel to compensate.

 

I have no idea what's telling what, just that the resistor mod makes your car run leaner, sometimes to the point of being dangerous

 

First... cold start enrichment is based primarily on coolant temperature, not on inlet air temp.

Second.... the typical resistor is 4.4Kohms... which tells the PCM the IAT is 57degF. That is usually colder than the actual air temperature. In a speed-density setup (93 only) that means the PCM "thinks" the air is denser that it really is. It therefore calculates that more pounds (mass) of air has entered the engine, and adds extra fuel. But the air entering the engine is actually hotter, and hence LESS dense, so less pounds (mass) of air has actually entered the engine. Since the PCM is calulating fuel based on a larger mass of air than is actually entering the engine, it is adding EXTRA FUEL and creating a RICH condition. In the 3rd Gen's, this was often a good thing at WOT, since they weren't already programmed a little too rich from the factory. An LT1 is already programmed too rich at WOT (typically 11.7:1) and does not need any extra fuel.

If you have a mass air sensor, it means absolutely nothing, since the MAF is calculating the pounds (mass) of air entering the engine, not the PCM.

 

Wait a Minute guys... first I need to know if the IAT increases or decreases its resistance with higher temps...


If it works anything like the Coolant sensor... then that means as the engine gets hotter the IAT resistance will get lower....

Now I recall the guys were inserting that resistor in parallel with the IAT... in this case scenario... if the IAT resistance gets lower as the temp gets higher... adding a resistor in parallel will reduce the resistance overall..

for example 1 ohm plus 1 ohm in parallell is not two ohms but Half an ohm...

The Ohms formula for parallel resistors is Rt = 1/ (1/r1)+(1/r2)
The Ohms formula for series resistors is Rt= r1+r2....... etc etc

Rt = total resistance
r1= number one resistor
r2= number two resistor


2nd thought... If the IAT reduce its resistance as the temp gets colder then this parallel resistance will efectively tell the computer the engine is colder.... if this is the case then it will work as expected

3rd thought.... I am not an expert but the IAT is a Thermistor and all the thermistors I have known decrease their resistance as the temp goes higher.... is the IAT a new type of Thermistor???

4th thought does anyone know if the IAT internal resistance goes up or down as the temp increases??

I will need that info to figure out wich way to insert the resistor to fool the PCM into believing the air is colder...... if the resistance goes down as the temp goes up... then we need to plug in a resistor in series... on the other hand if the resistance goes up as the temp increases than a parallell resistance will make it look colder..think as if you are conecting a LED. its polarity must be biased properly to make it emit light. oh and the resistor override effect over the IAT must be controlled, else it will create more problems than its worth...

Maybe I should generate a resistance/temperature table of a brand new IAT so we can compare it to a used one, this way we could use a simple Digital multimeter and a Temp probe to tell if the IAT is within factory specs.... That goes for the ones like me who cant get enough cash to buy a laptop and sofware just yet...for all you guys who have the set up ready with software and all...or scanmaster it would be nice to just track the IAT temp readings as the engine gets warmer from a cold morning start... compare those to a brand new IAT and see how yours measures up.



Marvin