How much more power will a better muffler give me?I have a DC one now.Any brand or type better?My motor is stock for now.Motor plans for 2010 are a FMF pipe/+4 timeing advance/Milled head/Reeds/Air filter upgrade.I don't want to wast my money on a better muffler if it is not going to help much over my DC muffler. I:I