What is the correct timing and frequency fo the Tengu 2520HS?

Usually the best timing for the Tengu 2520HS motors is around 8-9 degrees of timing (based on Hobbywing) and a PWM rate of 32 should work just fine. The best way to check if the timing for your motor and setup is correct, is by measuring the temperature after flight with a laser thermometer (temp gun) - it should ideally be between 40 and 60 degrees celsius.