bro, i can only tell u what the guy told me, i also stood over his shoulder just incase he was trying be a dicey f**ker but he angled the meter thingy to show and said watch the little red light thing as it goes up and the numbers are on the side. by 4000rpm it was over.
im putting a smaller muffler on ther going to get it tested again thursday morning (hopefully it will pass) and then ill be making my new 3inch exhaust over the weekend.
its all a little bit confusing to me lol