I am trying to put my first 1/10 pan car together to run in a 17.5 breakout class in my local club. I am on a super tight budget so I am trying to use stuff I already have were I can. Now for the question, will a Castle Sidewinder Sv2 work with a 1s SMC C-Max 5600 60C battery and either a Hobbywing eZRun 17.5 sensorless motor or Leopard sensorless motor. Am I just asking for trouble? Do I have to use a sensorless motor, from what I have ready if I try to use a sensored motor it will cog like crazy.

You can use it but you will need to power the receiver with either a voltage booster or receiver pack (LiFe 220mah is good), disconnect the red wire from the ESC to the receiver and you should be OK.

You will get cogging at low rpm and at start up because of the rollout you need with 17.5 or 4600KV motors, once you get under way it should work sensorless. You can only use sensorless motors (or brushed) with that ESC.

Thank you for the advice, I have to se if my charger does liFe batteries