justin_o_guy2 wrote on 07/13/12 at 01:53:15:Tighten it,well,, turn it the direction youd turn it to tighten it.,
Yeah, turn it right to raise the idle.
Turn it to the left to lower it.
The effect is fairly audible and easy to notice.
I just guess on mine, though they do have some smartphone apps, I have heard, that can record your engine idling and can ballpark (I assume) the RPM for you.