it works by stopping coolant flow through the TB, essentially cooling intake temperatures down, but frankly its one of the biggest wastes of money you can do on your car. save yourself the money and just dont buy one.
however, the coolant flowing through the throttle body is where some of the flow to the rear head comes from so if you block that off either at the TB or the LIM then you will allow the rear head to run hotter. to alleviate this problem you need to open up the area on the drivers side of the LIM that is where the remainder of the rear head flow comes from. this will balance it out and you can safely seal it all off.
