Sound measurements can vary widely based on mic position, geography, weather, etc. But at Laguna (the only place we run with a 101 window) we can make 101, usually with a couple db to spare with the normal exhaust, 90 with the turbo muffler. Most of the time we are 99, but there are usually a couple that get warnings for being at 100 or 101. If a car isn't running right, it can go over 101.
The Laguna sound shack is right past where most people do a shift to 4th, most of the problems are caused by guys waiting too long to shift.