| Dasrak |
The closest thing to what you're describing are the drake companion rules, which are sadly a complete disaster and close to unusable. I've never heard of a "racing drake" in specific; maybe it's something specific to a published adventure?
| J. A. |
There's a reference in Dragon Empires Gazetteer to the racing drakes of Goka, and another reference to these drakes in Hill Giant's Pledge.
Those are just brief mentions, and it's not clear which kind of drake is being raced. I'm wondering if there's more about this somewhere else, possibly including stats if the racing drake is a separate breed.