How can Racer travel great distance in short amount of time?
There's no evidence that might suggest he travels at amazing speed. As you said he just tricks people, that's his power.
However, it is also mentioned he always wanted to be the fastest and trained for that purpose so it would make sense for him to be fast.
We know he's asked to retrieve Jellal but we don't know if he's super fast doing it. The dude might just be the fastest one in Oration Six so that's why he's asked.