The folks at Hennessey have finally revealed the quarter-mile time on their mad-crazy Challenger SRT600 — and it's a pretty-stellar-by-Mopar-standards 11.9 seconds, with a top speed of 121 MPH. Although we already knew from our exclusive visit to the Hennessey compound , the Hennessey Challenger SRT600 churns outs 536 HP and 582 lb-ft of torque at the wheels, we'd been waiting to see just how fast it would be. Well, now we know, and we've got video from the Texas-based tuners to prove it.