You could disable it with: source
function disableAutoSave(){
wp_deregister_script('autosave');
}
add_action( 'wp_print_scripts', 'disableAutoSave' );
Also not a real answer, edit the interval in the WP-config:
http://codex.wordpress.org/Editing_wp-config.php#Modify_AutoSave_Interval
The autosave function itself is in wp-includes/js/autosave(.dev).js