The Shearer will hit more violently in the mid and makes the numbers people like to see, But the dynoport and FTZ have a broader smoother torque curve that makes more a bit more power around the 5-6k mark. Im thinking of trying my Trinity pipe that has a very similar profile to the dynoport with my Carl motor to see how it runs. I'll give up a little power at 8k for some more torque coming out of the turns.