[jQuery] jQuery FullCalendar Fetch Events Optimization

Hello All,

I was wondering if someone could give me some pointers to help
optimize my jQuery Full Calendar Code.  The issue i'm running into is
when I fetch a lot of events through AJAX (> 25), the browser stalls
and becomes unresponsive usually resulting in a message to the user to
abort the script.  I'm trying to avoid this error, and I was wondering
if there was something I could do in my function to improve the
loading time.

Here is a copy of the function I'm running:

//Load the Business Unit Calendar Events
function ajaxBUEvents(start, end){
        //Loop through the selected checked calendars
        $(selectBUCalendars()).each(function(i, cal){
                $.ajax({
                        type: 'POST',
                        data: {'startDate': start, 'endDate': end, 'buCals[]': 
cal},
                        url: '<?= 
site_url('AJAX/calendar_ajax/get_cal_events'); ?>',
                        dataType: 'json',
                        async: false,
                        beforeSend: function(){
                                $('#loading-dialog').dialog({minHeight: 100, 
width: 250}).dialog
('open');
                                $('#loading-dialog p').text('Loading '+cal+' 
Calendar Events');
                        },
                        success: function(calevents){
                                $.each(calevents, function(i, calevent){
                                        
$('#calendar').fullCalendar('renderEvent', calevent, true);
                                });
                        }
                });
        });
        $('#loading-dialog').dialog('close');
}

And here is a sample of the JSON that is returned, this is only one
event. Sometimes there can be 50+ events returned:
[{"id":4377,"title":"BWR - Lighting Affiliates Dinner -
Actualized","start":1259874000,"end":1259888400,"className":"BWR
Actualized","allDay":false,"editable":false}]

Thank you for the help!