launch question...1.83 60ft to soft?

my dodge weighs 7280lbs and im leaving the line at 20psi. ive been looking at other people's time slips with roughly the same weight trucks and their 60ft times are in the 1.7X to 1.6X. should i be launching harder? i broke my first billet opie shaft and do not want to do the same to my new tcs aermet shaft. what do you guys think? should i bump up to a 25psi launch or is that shock loading it too hard?



here is a pic of my time sheet.

any advise would help. also i dont think im having traction issues, so im not counting that as a factor.