ArkansasGTO

Hey guys, I am a new owner of a 04 auto GTO. Another family member of mine drives a 02 z28 that I am used to racing at the nearby 1000ft track. Now I know that GTO's have bad wheel hop and I know that statistically an auto is slower. But my problem is that no matter what I do I cannot run consistant times. I'm not talkin' like within a few tenths either. I mean it seems that every time I go race the car my time slips are like a staircase, I know the launch is critical but my launches are all the same. My time from the first race to the last race usually is the first race being about a second and a half faster than the last...also I have noticed that my finishing mph is dropping around 7-10 mph towards the end of the night. Now let me also say this, by no means am I mistreating the car or doing somthing I'm not supposed to (as far as I know) and I'm not running back to back, I let it cool off after every race. Also another bit of imput the car has only 20k miles on it and was drove by an old man before I got it and to the best of my knowledge there is nothing wrong with the car, it is PERFECT. The car is also stock except for a K&N intake. My question is this: Is there somthing in my computer that notices drag racing therefore reducing power to take away most chances of breaking somthing?...anything that would cause me to run an ok time the first run but never be able to match it again? I just do not think that it is driver error knocking me down that far...any comments are good ones at this point...