vacuum gauge
 

I installed a vacuum gauge, what should it be set at when at idle? And wot?

well idle varies from type of cars..im gonna take a long shot and say like 80hg? WOT should be 0 cause your not running and type of FI. Some one correct me if im wrong

A simple way to answer your question would be to quickly state what a vacuum gauge does: It reads the vacuum created by the pistons in the intake manifold. The throttle plate generates the vacuum because it trys to keep air from getting in. So, in theory, at WOT, the vacuum gauge should read very little to 0 inches of mercury, and at idle, it should read 16-20 depending on your compression of the motor, and if you blip the throttle at idle it should spike to 22, maybe 24 for a brief moment. On a boosted car, obviously, at WOT it would move above 0 inches of mercury into the pounds per square inch range :)