Either test the sevo in the car.
Or you need something like this:
Test your motor system without using a transmitter and receiver. The SerCon can be used to test servos and throttle control on ESC's.
* Manual mode: turn the knob with different speed, check the reaction time.
* Neutral mode: make the servo go back to the neutral point.
* Automatic 'window wiper' mode: Servo swings like 'window wipers' to their full angles.
* Connect up to 1-3 servos simultaneously
* Test 1-3 servos consistency.
* Connect 1-3 ESC's & test and compare reaction time respectively.
* Connect 3 servos of the CCPM helicopters and select servos.
MiCk B. :-)