I am getting into 1/12 scale now that a track is back on line near me. I've seen plenty of people ask about roll out and be given suggestions for where to start, but I want to know how to apply the result. I am running 17.5 with 47mm tires. The track is asphalt with about 100 foot back stretch. What should the roll out be compared to? I prefer to understand the application rather than just "start with 90".

Can someone explain this?