I am thinking of getting a Big Gun system, what do people think that have one, is it overly loud, can you tell a big difference in power,is the top speed higher, and finally do you have to jet the pilot,needle and main or can you get by with just the main and how much bigger than stock, I ride at 1500-3500 above sea level.

What kind of quad? You should only have to mess with the main and needle.

The Big Gun Utility Quiet Series is FAR from quiet. I think its 108dB. They are ceramic coated which helps with cooling.

I've got a Big Gun Slip on for my Raptor. The pipe is LOUD. Sounds really cool tho! Flows much more air than the stock system could ever hope to. Dont know if there's much power increase yet as I havent been able to ride much since I put it on. I jetted up the mains and the pilots. Went to a 25 pilot and 145/150 mains, stock was 140/145 if I remember correctly. I didnt mess with the needles as there seem to be no flat spots. I am still running the stock airbox/filter with no mods. I'll play with the airbox when the weather dries up again.

Thanks Guys, The system is a headpipe silencer combo for the Prairie 650, they will ship them at the end of the month, $349.00 for it all, I have heard a Raptor with a White Bros. E-series with 12 disks, is it louder than those, I don't want one if they sound like the Cobra systems, thanks again.