[racket] Coding in a Scheme subset?

When I recently decided to learn a lisp, I spent many hours researching various Common Lisps, Schemes, Clojure, etc. and determined that Racket was the best fit for me; however, I may want to make use of other lisps for particular situations (e.g. embedding in another application, etc.).

For those of you who are much more experienced with Racket than I am, how feasible is it to partition your code into one set that is fairly portable scheme and another set that makes full use of Racket specific features? I don't anticipate wanting to port an entire app, but I can imagine wanting to make use of a large library of utility code.

Thanks,
Brian