I'm trying to meet a 94db limit. I already have a Pro Moto Billet "Endo" S/A installed on my stock 2008 YZ40F exhaust. PMB sells an Ultra Silent Insert for the "Endo" ($49). I'm thinking about picking one up. Have any of you used one of these PMB Ultra Silent Inserts? Will it make 94db? Thanks in advance for any help!!