I am in the market for a new silencer. The stock one is worn out its welcome and is probably plugged anyways. The question is which one should I get..the Power Core II, the Power Core II shorty, or the Turbine Core. From what I understand, the Turbine is the only one that is a spark arrester as well. Do I need a spark arrester for some types of racing such as hare scrambles and poker runs? Do I need one in order to ride in ORV parks? Thanks in advance peeps...