Better alternative to pmap in Clojure for parallelizing moderately inexpensive functions over big data?

Using clojure I have a very large amount of data in a sequence and I want to process it in parallel, with a relatively small number of cores (4 to 8). The easiest thing to do is use pmap instead of map, to map my processing function over the sequence of data. But the coordination overhead results in a net loss in my case. I think the reason is that pmap assumes the function mapped across the data