Is there a way to change the time in a replay without having to redo it?

Yep, there is.

You need to quit toribash, go into your toribash folder and there to replays.
Open the selected replay with notepad.

You will see a round like this:

NEWGAME 1;500 50 15 0 0 15 250 0 1 wushufixed.tbm 0 0 150 80 0 0 1 0 2 0 0 0 0 0 0 0.000000 0.000000 -9.820000 1 0

The first number is the matchframes, which is 500 in the example.
Modify that and the reply will have more matchframes.

Thanks slipanc i really appreciate it.