Just a note, many times a customer notices that their tune feels "slower" because the car is smoother in the RPM rather than a sudden burst of power. This effect happens many times.
However, if you have a wideband air fuel ratio gauge can you please tell me HOW rich the car is running? I need this basic data to be able to help you out. If you want, you can remove some fuel from WOT to lean it out and see if that helps. Does your car have an O2 sensor from factory?
I can help you easily, but I and anyone else who wants to help needs the basic information, AFR. Without that, we don't know HOW much to adjust fuel.