give all the facts, it dont add up.
car put what, 260 to the wheels?? a stock gtp puts about 200 to the wheels and can still trap 95.
only thing i can think of is crazy amounts of torque management in the tune.
if it was at sea level, and it was not crazy hot, either something is wrong with the car, or the tune is off. i would think your mods should deff trap in the 100's