New SB-21FH for the OS SPEED 91HZ-R 3DPosted on October 11th, 2011
These tuned mufflers have been designed for increased torque. We recommend tuning your rotor speed and gear ratio to the following rpm range (OS 11,000~14,500 and for YS 12,000~ 15,500). This is also the preferred rpm’s to use during heavy cyclic and collective loads as in 3D flight. Torque will drop off after 15,000 rpm OS and 16,000rpm for YS. The NEW SB-21 FH is designed for the OS 91 SPEED HR-Z 3D and has no pressure tap.