HAS ANYONE DONE DYNO TESTS ON AFTERMARKET CANS (SLP, SNO STUFF, MBRP, SUPER Q, ETC.) ON XP 800'S WITH STOCK PIPE OR DOES ANYONE KNOW OF ANY WEBSIGHTS OR COMPANIES THAT HAVE? I HAVE HEARD THAT YOU LOOSE POWER WHEN YOU ADD AN AFTERMARKET CAN. WHAT IS THE TRUTH.