I have been on these forums for several years, and although I like you guys a lot, sometimes we quibble over the small stuff LOL!!!
IAT's have always been proported to be this miracle secret. I remember when I had my first car back in 1997; people were taking the IAT and moving it to their grills on thier NA cars and thought that they were gaining horsepower! I admitted, I tried it too
All an IAT does is provide an insignificant input the the ECU. The ECU uses the IAT in conjunction with the EGR and the ECT to determine whether or not it needs to pull or advance timing. Generally, the IAT provides the most impact during starting. The ECU will assume that it is a cold start and advance the timing if the IAT and the ECT are within 15 degrees F of each other. After the ECU deetermines that the car is warmed up it relys mostly on the ECT and EGR. The result of the IAT is usually rather miniscule but if you disconnect it, the ECU gets really pissed.
Note: IAT locations are like Brittney Spears' singing career; it just doesn't matter!
Place it somewhere in the intake tract. Best place is to tuck it under the filter. Don't put it after the turbo. You will have to take extra precautions to ensure that there are no boost leaks, and even if you do the extra work of ensuring that you have a good seal; in the end... see note above.