Retirement tax questions

my business shows 65,000 of income after deductions. I set 10,000 as the employeer contribution to my solo 401k and my taxes only went down 990.  Between me and my wife we are in the 22% tac braket and then there is the 15% self employment tax.  For every 10,000 contributed, I should see 3k of taxes go down.  Something seems very broken in turbotax.