i didn’t use a curve in the timeline. I had two keyframes set to a value of 1 so it would immediately put you at full speed. The reason i used a timeline instead of just a straight value was to have the value applied over a time-span. you could use the update pin from the timeline node and a variable to achieve the same thing, i just used the value in a timeline track to make it simpler.
Edit: I just noticed there is a bit of ramp up with the example i gave but i believe its due to the max acceleration.