Maybe can be so easy but at some servers, if you do some good lap automatically says " good lap!" or something like that. Or sometimes, it put the time sector instead of the split time. For this, i guess, i can to build a little program for put on the top of the screen my best lap with sector times and see the diference on each sector for a single lap, compared to the fastest lap of the session. it can be possible?? regards.

Yes it's possible to do. If you want to write something yourself then you need to look at using InSim (check out the FAQ and good practise thread for more information).

However, most servers use a program called LFSLapper, which can already do this (amongst many other things) and can be found here:
http://www.lfsforum.net/showthread.php?t=25756

damm it can be a issue becaus i amusing /30000 for the rev lights.

If you're using InSim over TCP (which recent versions of LFS, and almost all recent InSim clients use) you can make multiple connections to LFS