getting a longer acceleration phase

what is the best way to prolong the acceleration phase in a 100m? I get to Max V at 30-40m and from there it is downhill. What should I do?

Why do you want to prolong your acceleration phase? Work more on max velocity. The faster you are the longer it will take you to hit top speed. Speed endurance should also become a focus. What is you 55/60 and 100 time? If we know both we can then say more.

I don’t know what my 55 or 60m time is, but my 40 yard dash time is - 4.6-4.8 (HT) and my 100m time is 11.8-12.0 (HT)