"Hindy is right (as usual!) in that ALMS radios are not allowed to be encrypted during the race. Likewise, they are not allowed to run in digital mode during the race. In practice sessions, there are no restrictions, although I have no evidence to suggest any teams run any form of encryption (I do know that Corvette have gone digital in practice then back to analogue in the race before). Its the same deal in NASCAR and Indy.
For WEC, I am quite confident there are no such restrictions. There are no restrictions in any other european endurance racing that I've seen (eg ELMS, BES etc). I do know that some WEC teams used digital at Sebring, which caused a bit of a stir. Again I have no evidence to suggest that any WEC team uses encryption, on analogue or digital. Several of the WEC teams actually use digital radios (Audi, Rebellion, JRM, ADR-Delta, Status, Starworks, Pecom, AFCorse, Krohn, Felbermeyr) but the radios can operate in digital or analogue mode, and most operate them in analogue mode than you can still scan - I understand that only Audi and Felbermeyr have used their digital radios in digital mode so far this season.
And and if you're still reading this, you should find all the frequencies you need at this site: http://groups.yahoo.com/group/uk_motorsport_frequencies/
You'll also get the frequencies for things like that now famous voice of the ACO race director.
If you need some help, just drop me an email.
HTH,
Jim"
Fonte: http://radiolemans.0157.org/content/listening-wec-team-radio