IAT Resistor Mod

[bszopi]

IAT stands for Intake Air Temperature. It is a simple thermistor that changes its resistance according to the temperature it is at. The idea beind this modification, is that by changing the resistance to that of a cooler interpreted reading, you will get more fuel. While it is true that you will dump more fuel...its false that this is a good idea. Running rich is bad for performance, so you are just wasting your time with adding more fuel in this fashion.

The stock computer already compensates fuel as it is, so trying to trick it into giving you more fuel is completely worthless. If you dump too much fuel, via switching to a colder resistance on the IAT while driving, you may even notice a puff of black smoke out the exhaust. Then, the O2 sensor will detect the overly rich mixture, and reduce the injector pulse width. This totally defeats the purpose or the IAT mod.

[OverRide]

In most newer cars, the IAT sensor does not adjust fuel directly. It adjusts the timing. When you look in the computer it will have a IAT vs timing table where for each temp you can tell it to give you more timing or less timing. This is the priciple behind the happy knob. People chance values in the table in certain increments and then get a know with resistors that match each temperature. then they can select the timing advance/retard

[OverRide]

this is not really true, the IAT more controls the timing the the fuel

[12mac1767]

What about if you are running between 2500-5200 RPM around an oval track, will the o2 stay clean enough, also there is no EGR valve on this motor.
The TB coolant is bypassed, no power steering, and everything I can strip off, is taken off.

[SappySE107]

I have yet to see anyone put a resistor in their IAT plug and get more power. The computer does change timing based on coolant temp, and air temp, and a lot of other variables. Its also affecting fuel with the coolant temp and air temp. The timing advance doesn't help you either (proven on a dyno, tuning the spark table). In fact, I have found more power reducing advance and leaning the motor out some than going for the most advance I can run. Do you know what you are doing when you pick a resistor? How did you come to that conclusion? Can you repeat results?

O2 feedback does not adjust spark timing. Your O2 is fine and none of that other stuff matters really.

[asylummotorsports]

This discussion/argument has been going on for quite a while and it has been my experience that these things are notoriously inaccurate and you can try to fool them all you want, there is NO performace gain That anyone has ever proven.
I have tried mine in ice, simply laying behind the battery, in the intake tube, and hanging down beside the trans.
ALL ON THE SAME DAY at Toronto Motorsports Park!
The difference in my times that day. Quickest 15.92. Slowest 15.98. Total of 8 runs, two in each mode.
Absolute waste of time messing with that thing.
FWIW

Eric