@CaptFoxworth19 post your unlisted attempt and tag me on it

@SemedianIndustries thank you for the help it truly is but the formula didn't work on my engine design

yes

@SemedianIndustries do you have an aircraft that uses this kind of stuff and what is the name so I can search it, thanks.

@SemedianIndustries thank you so much, I appreciate very much!

arctangent function (in degrees) vary between -90 and 90, you put a minus before so it goes from 90 to -90
-90<-atan(x)<90
as you want this to be used in a engine to max out thrust at "x" speed, you want the fuction to vary between 0 and 1, so you do this
-0.5<-atan(x)/180<0.5
0<atan(x)/180+0.5<1
The point where the curvature of the function flips is when the thing inside the arctangent function is 0. So imagine you want that top speed to be 300kts, and the x is already converted to kts (1.9438*IAS if you're wondering), you do this
0<-atan(x-300)/180+0.5<1
When the speed is nearing the limit you set, the output of the function lowers just before it.

I hope this helped

@SemedianIndustries enlighten me please My Mathematical skills is not that yet complicated, I would kindly accept it if you will teach me about it or give me an example, thanks

Use a arctangent function