any time you change the wave length of the exhaust it going to have an effect on the power of any combustion motor. just like when you re-pack your silencer, it has an effect.
i just don't want it to bog and not blow up on me, i been having bad luck with that lately, lol. i know i took silencer apart today and all the packing was soaked in oil.....
Have to compare apples to apples. If both have fresh packing then you can compare. More sound isn't more power or better running. JMHO, your results may, and will, vary.