Check Just googling but:
C50-MAXX 12 12 Cells 3600Kv 15/72 pinion/spur set
C50-MAXX 14 14 Cells 3300Kv 15/72 pinion/spur set
C50-MAXX 16 16 Cells 2600Kv 15/72 pinion/spur set
Only the 2600kv might take 5s but that is still almost 50k...
You might want to consider this...
http://www.impaktrc.com/product_info...e3478e7d656978