OK, I don't really know too much so, easy.

I have a 06' GT auto with a Roush S/c and I'm really pleased with it overall. But I have noticed quite a difference in performance with the tranny. Maybe not the tranny but I think so.

Most of the time I could just mash the gas and it would burn the tires until 3rd gear but sometimes it will barely chirp them from a stop. It feels like maybe the transmission is starting in 2nd gear, I don't know.

What I do know is that I never have this problem If I manually shift it from 1st-2nd-3rd-D. Has anyone else experienced this with their auto?

 

Just a thought..have you verified TC status. I am N/A but I am not stock, I have experienced my TC kicking in without the rear end breaking loose or even coming close. My personal theory is the RPM's are climbing at a rate that the computer thinks the rear is spinning. Apparently all the tuning we do has not addressed such a thing. However this is just my theory.

 

That thought crossed my mind as well. The TC light is on indicating that it is disabled though.
Also, I've found that the TC doesn't react very quickly. I've slid the car around a corner with the TC on.