Depends on
a) if use ESC Boost and/or Turbo.
b) if you have good motor heatsink and/or fan
a) if No Boost/Turbo, 17.5 with 4.16 will be very slow (slower than white pig 540)
If use Boost/Turbo, then FDR really depends on ESC setting. Usually around FDR 2.8 - 3.5, and 3.3. is a good starting point.
b) And if use lower FDR like <3, need very good heatsink/Fan or motor get hot fast ; and the car be very fast.
(of course, depends on ability, tires and car setup)
If use Boost/Turbo, ask friends at track side for nominal settings.
Watch your motor temperature all the time after each run to see if your boost/turbo is too aggressive for track+weather condition.
