Hi Ron,

I can't speak for the other units but with my FAST XFI you can turn closed loop on and off and you can set a minimum temperature to start closed loop operation. The learn feature is even more flexible in that you can turn it on and off or set parameters for when it learns. Those parameters can be temperature range, throttle position or RPM ranges. You can also create as many as four different tunes that are stored in the computer and can be changed by an external switch. Of course you can always load different tunes from a laptop as well. I'd suggest you go to one of the manufacturers websites and download their controller software. Most of them this is a free download and then you can load a canned tune and poke around.