Technically, the max turbo clocks of the base 13 are 2.7 and 2.4 (single/dual), while the base 11 are 2.3 and 2.1 (single/dual). The IGP of the 13 also turbos to 1200MHz, about 50MHz faster.
That's not going to make much of an actual performance difference in everyday use, however. Imperceptable while playing a game, and only noticeable (even so, not by much) when performaning a taxing task (i.e, rendering videos).