get a Diablo tuner... I dropped almost a second off my et in my old 06 AWD Mag R/T. My best time was 14.06. Leave it in D. You can change the shift points as well as frimness of shift w/ the tuner. I also changed my thermosat to 180* changed the fans, removed the goofy engine cover and iced the intake between rounds (not sure if that helps or not) because it's usually hot and humid here in Md. A 2wd should run 13's easy.