It's been about 10 years since I last raced off-road, but I'd like to get back into it. I plan to enter the ULTRA GP at Strader Ranch in Oregon June 26th. I plan to race my 2002 YZ250, so I'll need a spark arrestor. I've been looking at the Pro-Circuit SA / Silencer and the FMF Q-Stealth. As per the race flyer, I need to pass a 99db maximum sound test. I'm not worried about making my bike quiet for a race, just passing the sound check and having the USDA approved beef (er, I mean USFS spark arrestor). Will the Pro Circuit spark arrestor pass a 99db sound check? Will the FMF Q Stealth pass a sound check? Which system is smaller? Which system weighs less? How much does each system change the jetting? How much does each system change the power?