Depent of the rpm of your engine.
If your engine makes 5000 rpm, the IR2153 must ocsillate at least at 2500 puls/m on one of the outputpins.
The bridge makes two positives pulses from the output of the transformer to load the capacistor.
Every spark nead atleast 1 positive puls from the bridge to load this capacistor.
Better is to chose a 10x higher ocsillate of the IR2153