Rashiki

I was just wondering what exactly making the IAT sensor think the air is colder does? I know cooler air is more dense, allowing for a more powerful charge in the combustion chamber, but does the car add more fuel or advance the timing a degree or two or what?

I've hit a brick wall as far as finances go, so i'm not driving around much just to save on gas, and was thinking of some inexpensive ways to boost a few horses. Can you modify the IAT sensor to think it's cold with a resistor from radio shack? Car and mods are listed below. I have not yet gotten the LT4 knock module yet.

Thanks in advance,
Tim

Hotwire

the motor does advance the timing and richen up the fuel a little to compensate for the colder air it thinks it's getting.

a lot of guys w/ s-10s are running 4.7k ohm resistors in the iat socket, some say it works, some say it doesn't. guess it just depends on how sensitive your seat of the pants is...

Think the 4.7k makes the computer think it is below 60 degrees. Kinda like leaving the rich choke idle going on a carberautor.

good luck.

one thing you can do, take the iat and throw it in the fridge for about 20-30 minutes, pull it out and measure it w/ a ohm meter, then match it. I've also heard some of the newer obdii cars, if you make the car think it is too cold out, it will not allow the a/c to operate due to freezing up problems.

Injuneer

On the mass-air F-Bodys (94-97) the IAT sensor is not used for air mass calculations (and hence fuel calculations) like it is in the speed-density models (93). The MAF sensor is the only measure of air flow and it has its own air temp sensor so that is can measure the current required to heat the incoming air up 100degF with the thin-film conductors (don't worry.... it only heats the air actually touching the wires by 100degF). If for some reason you lose the MAF sensor, and the PCM has to default to speed-density, then it will need to use the IAT sensor, but not otherwise for fuel.

The need to "choke" the engine.... e.g. add extra fuel on cold start, is primarily a function of the coolant temp.

I believe there is a mysterious 3deg of advance that people have never been able to track down, and it is sometimes attributed to inlet air temp. Not sure if the LT1_Edit guys have ever tracked it down.....

I remember seeing a post about a dyno day by a club... maybe in Georgia, and everyone who tried the 4.7Kohm resistor in place of the sensor found they lost HP.... this goes back at least three years, so not sure where to find the documentation.

Rashiki

If the IAT doesn't do anything unless it's on backup mode, why does SLP sell a little resistor for the IAT sensor... i'm confused...

shoebox

Because they like to make money from ignorant people. A few cents and a 4.7k ohm resistor does the same thing.

chasmanz28

so relocating the Iat sensor as i did was a waste of money? it was to help pull in cooler air and keep the heat away from the iat, now im pissed