Most likely the traction control. Had mine into the shop a few weeks back as I was concerned it might be a fuel issue, as in not getting enough. Most of the time on the street I leave all the nanny stuff turned on so when the guy sitting on my shoulder with the horns says "do it" the car has the halo and says no.
Now this isn't a subtle loss of power, this is a bang your head between the head rest and the steering wheel thing, violent. Usually when it starts making peak torque (3750rpm/737 ft lbs of torque) and the wheels start spinning.
I took it to my tuner/shop and we had already somewhat come to the conclusion that the issue was the TC. He took it out and data logged it and it did the same thing to him (thank God, not a driver error issue). He then tried it with the TC off and had no issues with power loss.
666 EVIL RWHP BUILT AND TUNED BY SHIFTED PERCEPTIONS INC.(SPi)
416 Forged Stroker, E-Force Supercharger, Blower Cam, Rotofab CAI, Stainless Works 2" LT Headers and 3" Exhaust, LPE ZR1 Twin Disc Clutch, DSS 1400 HP Axles, Pfadt Performance Kit Stage 3.