Originally Posted by BlazeRex
To correctly run SD, I would agree that post turbo IATs are much better, but I feel like you could get it pretty close with estimating intake IATs. Of course there are other variables that at the same pre-turbo IAT can affect true air charge temp, hence why it is recomended to use post turbo located sensors. That's up to the person's comfort level if they want to leave it pre-turbo and take a chance; or properly relocate it.
Another unspoken issue here is one of poorly placed and/or heat soaked post-turbo IAT sensors.
This part is discussed in the COBB SD guide (I can't say for the other SD offerings).
And yes, it's a reasonable estimate under certain conditions...and its up to everyone to decide how wide the ballpark they will accept is.
My main gripe is that it seems many people don't understand the value of accurate temp modeling. Look at the default charge temp comp for COBB SD - that's based on the idea gas law. Going from 86 to 50 degs F is 7% difference...that's a whole bunch.