Same muffler - It was a change in where the power is. The more you open up an exhaust the the more low end torque you will lose, but in retrospec you will gain more at the top of the curve. The loss is not much when we are talking about large displacment engines with torque to spare but in this case I was no longer pushed back in my seat so it was noticible that there was a loss in the torque on the bottom end. It was ok if you stayed at the top of your rpm scale all the time but that is not where the fun is in IMO.

-marc