4k RPM
 

Is it true that rotary have more torque as it reach higher rpm. I notice in my n/a i don't feel much torque between 2k to 3k if I plan to push the car. As 4k and on it creates good power? anyone can explain that to me?

Its as simple as yes, the engine was made to spin high and produce power while spinning high.

yes it creates more power as the rpm's increase but only up untill roughly 7k rpm , but once you have reached around 7k there is not further power gain .

thanks and I love the sound of an rotary hehe.

Its more to do with the tuning than the intrinsic nature of the motor itself.

More or less all motors are most efficient at about 2K rpms, unthrottled, but if you have a lower-efficiency motor with small displacement that HAS to rev to make any power you tune it for a higher rpm range.

And for that matter, turbos kind of dictate revving high unless you want 200 hp at most.