Hill Sprints Distance?

I thought I do my hill sprints to improve my acceleration mainly, that’s why I’m only doing short distances of 45m (50yds)

The hill I’m using is not very steep, but it makes my acceleration considerably slower.
If you take about 6.00 in the flat, is it ok if it takes you 9.00 (150% of the time) for the same distance on the hill. Or would that mean: find a hill less steep?

Should the time covered for a hill sprint with that focus be 7 secs or less, or can it be longer like 9 or 10 secs?

THX!

Found the answer - sorry for not reading first…

http://www.charliefrancis.com/community/showthread.php?t=1855