Great info and testing.
Do you feel as if you lost any top-end? I guess the real way to answer that would be to see what BB has to adjust. They would see a drop in CFM and vacuum at WOT at upper RPM. For that matter, they should be able to analyze any changes throughout the RPM to determine if any power was picked up in the low end. Calculating the changes in flow can create an estimated power curve chart to make comparing easier.
I haven't really taken her out and opened here up on the interstate but from what little bit I have had her on the big road I would definitely say NO.
I have to be more careful now it seems because if I'm not paying attention she will get away from me... I will look down and be 10-15 over the speed limit and not realize it. So she just seems to want to go more now.
I don't have a BB tune... it is a Diablew tune via a Diablo sport tuner.
I did ask him if there was a big difference from the last tune...
Me... "Just out of curiosity was there much of a difference from the last tune???
I'm just curious how much of a difference the headers and y pipe made."
Lew... "yeah I made a bunch of adjustments.. airflow, fueling, timing, WOT fueling, WOT timing, etc.."
So who knows... maybe he's being completely honest or maybe he's just blowing smoke to make me feel like I'm getting my money's worth... lol