It will be different from bike to bike, depending upon location, altitude, dyno and other factors. I'd would install that slip on and go from there. Some bikes benefit from a remap after a slip on and many won't likely need it. I personally was not able to get away with NOT retuning my bike after I installed a slip on and air filter so I had to pick up a PC5 and take a trip to the dynoman. Very glad I did. You many have different results. In any event, that is a great looking exhaust. :thumbup