First off let me say that R/T has nothing to do with 1/4 mile time so don't even worry about that. My first times at the track I would sit there and let the other person leave and then I would go. Your time starts when you break the beams.

As for your times yeah the 60ft. is not that great but I think that you could greatly benefit from a progressive nitrous controler that would allow you to spray a little shot like maybe a 50shot in 1st and 2nd to help spool up that big turbo you just put on there.