Is that the video you referenced being in the other thread? I couldn't find it elsewhere.
Its hard to tell a lot from that video, but it doesn't look like the car is transferring weight as well as it could be. (Though you're hooking a lot better than that Ranger-LOL). Are you leaving on the brake in that vid?
What RPM do you leave at? What does your front suspension consist of?
What does the car run 1/8th and 1/4?
Moving the battery might help, but there are probably other changes that would be more beneficial at this point.
Steve