GM V6 IAT HAI trick?
 

After just coming back from a great place, the junk yard, my friend and I were looking for parts. I came to notice, that the GM V6 and V8's have the IAT (Incoming Air Temperature sensor) just like the Saturns, Cavaliers, and Sunfires. Has anyone out there experimented with the bigger GM vehicles and installing an HAI (Hot Air Intake) or tricking the IAT? The way I figure if the new Corvette can get high mpg in lean mode, can this be done to the huge numbers, of Malibu's, Lumina's, Camero's, and Grand Am's out there?

I got marginal gains from blocking my grille and taking the lid off my air cleaner box to pull warm air from the engine bay in my V-8 pickup truck. My IAT's run ~ 50F over ambient. I have been considering rigging up a proper HAI for winter driving.

-Jay

In a recent discussion on gmfullsize.com, multiple users said that they got their computers tuned for running leaner, one user mentioning as lean as 15.7:1 IIRC. So, if they're not full of crap (and if the tune didn't do anything special to make it work other than just changing the AFR), it should be okay to lean it out a little bit.

but you aren't changing your a/f ratio.

the resistor trick (I have heard) doesn't work on all vehicles because the oxy sensor on some vehicles will compensate for the miss reading on the IAT sensor.

the WAI simply causes less dense air to come into the engine which has less oxygen in it which in turn uses less fuel. the a/f ratio is the same but in a way it is taking some displacement away from your engine. it makes your car run like you have a smaller engine.

*edit* you will get similar results as if you have increased your a/f ratio

You're right, BEEF, I was responding to the bits about "tricking the IAT" and "the new Corvette can get high mpg in lean mode". Normal WAI does not cause lean mixture.

Also, tricking the IAT probably won't help, because as you said the O2 sensor will provide data that results in the computer compensating. That's why a custom tune would be necessary.

I have heard once before that one of the conditions for lean burn on the VXs was for the IAT to be over a certain temp. don't know if it is true but if the corvette is made the same way, it would make sense for a resistor to work in that respect.

I have seen pretty good gains from both the grill block and the WAI which my WAI isn't so warm anymore. I haven't seen triple digits on my IAT sensor in a while.

Speaking of WAI, I had an idea the other day...I realized that my grille block makes my car's thermometer display inaccurate, because the sensor is in between the grille block and the radiator and not exposed to outside air. I figure, why not move the sensor to the intake? Then I'll have OEM IAT display on my dash next to my speedometer!