ORIGINAL: mjorgensen
Just for a little info we just finished a SRT with the Kooks headers and X-pipe, no cat back yet, a diablo tuner and custom stall converter. The car only has about 150 miles on it and the owner has not been able to launch without blowing the tires of. He is running with the traction control on and seeing 13.4 @ 109 plus. The car should do 12.90's if he can get it hooked up. Looking into halfshafts and drag radials now.
What have you seen from others?
Headers, drag radials, tune, and a stall (what rpm?...3200?) in a 425 hp car should do way better than 12.9. I am thinking 12.0-12.4 depending on track conditions and DA, plus some good break in time. On good weather days my 375 rwhp 05 GTO (see sig.) was running 12.teens. I would hope and expect the 6.1 Hemi to do way better than the 12.9 you mentioned.