The biggest thing I've found with raising racers successfully is to leave them alone. They're very skittish, and most of the time they won't eat if someone is watching them, or even if someone is in the same room with them. I've raised multiple groups of hatchling racers on crickets and day old pinks. Most took to feeding right off the bat just as long as I left them alone.

Coachwhips are a completely different ballgame. What will work for one won't work for another. Because of their slender body type, the hatchlings in particular need small food items or they'll regurge every time. Also, some are local specific as far as what kind of lizards they want. Adults are fairly straightforward (i.e. if it moves, they'll eat it).

Kevin