My buddy just pro charged his 09 challenger srt8 and put a blower cam in it to along with headers and 3" exhaust a different tune on it and a boosta pump. He went to a dyno shop tuned it and it has 580rwhp which is pretty good. His problem is when we went to the track the best he could get out of the car was 12.88@111mph it still has the stock suspension on it and tires to. He thinks it should be in the high 11s. Whats his problem. and its a 6 speed to. any help would be great. Thanks