That is precious little to go on. Chances are your best bet is to contact the manufacturer, but if its a direct-to-consumer internet bike, you may not get anywhere.
Your motor controller should list its peak amperage and continuous amperage ratings. Both of those coupled to your battery voltage will give an idea of a) acceleration and b) top speed. Likewise, if its a direct drive hub motor, we'll know its acceleration is less than if it were a geared hub motor. Better pics of the whole rear wheel would likely tell us DD or geared (DD hubs are the big pie plate-sized kind).
Speaking generally, a 48v system with a geared hub is probably going to peak out in the 25 mph ballpark on 26" wheels. 20-22 (ish) on a 36v system. So lets say you are getting up to 25 on your bike now and it has a 48v battery... there's not much point in looking for hot rod settings because 48v is only going to get you so far.