Put Variable within FormData

How can I put a jquery variable inside FormData?

Example:

I have a CKEDITOR, however I am not able to save in the database, but I am using the ajax send format, which I found on a website, to upload images, and this way, uses FormData, however I do not know how to do the CKEDITOR data, to be registered in the database.

Follow the code:

$(function () {
    $("#load").hide();
    var enviando_formulario = false;
    $('#form-post').submit(function (e) {
        e.preventDefault();
        var post_content = CKEDITOR.instances['post_content'].getData();
        var obj = this;

        var form = $(obj);
        console.log(obj);

        var submit_btn = $('#form-post :submit');
        var submit_btn_text = submit_btn.val();
        var dados = new FormData(obj);

        console.log(dados);

        function volta_submit() {

            submit_btn.removeAttr('disabled');
            submit_btn.val(submit_btn_text);
            enviando_formulario = false;
        }

        if (!enviando_formulario) {



            $.ajax({
                beforeSend: function () {
                    enviando_formulario = true;
                    submit_btn.attr('disabled', true);
                    submit_btn.val('Enviando...');

                    $("#load").show();
                    $('.error').remove();
                },
                url: form.attr('action'),
                type: form.attr('method'),
                data: dados,
                processData: false,
                cache: false,
                contentType: false,
                success: function (data) {
                    $('.info').remove();
                    volta_submit();
                    if (data > 0) {
                        $('#load').hide();
                        $('#form-grupo input').val("");
                        $('#form-grupo textarea').val("");

                    } else {
                        submit_btn.before('<div class="alert alert-danger error">' + data + '</div>');
                    }
                    $('.suc').remove();
                },

                error: function (request, status, error) {
                    volta_submit();
                    alert(request.responseText);
                }
            });
        }

        return false;

    });
});