Any idea is my Hub dyno maxing out?
The brake is maxing out. As you can see it is at 100% for a long time.
Are you sure the PWM settings is correct? Test using the slider and measure the voltage when at 100%. You should get close to 192V.
Also make sure to enable the option "Compensate for inertia effects during acceleration". Otherwise your readings will be too low.
Can i put maximum pulse widht up to 100% ?
Now its only 60%.
2pcs CC160 should able to brake 3200Nm from hubs and with 3.91 ratio there is only ~2200Nm now.
You need to check the SportDevices PWM spec. But for sure it should be more than 60%. Max PWM duty should either be 100% or maybe slightly below.
With 60% max PWM duty you will not get 100% brake.