Based on the Sonic 540-M4 competition motors the new Sonic 540 DR has the outward appearance of a standard 540 motor but appearances can be deceiving. The R&D dollars and time were focused on internal changes such as an improved stator profile, thicker laminations and unique materials, all housed in a revised lightweight can designed for improved cooling. Available in winds from 2.5 to 4.5 turns in .5 turn increments these motors are designed for use with 2s lithium power and also feature adjustable timing for added tuning capabilities.