Grep a rar in cygwin

I want to make grep text files inside rar without extracting the rar file to disk, I tried a couple of combinations with pipes, however it didn't work, I tried for example

unrar e myrar.rar | grep mysearchedline

however it actually opened it to disk, I don't want to open it to disk, I don't have enough space to open it (its real big with real big logs).

Thanks.