Well, surely working on these research projects has grounded in you a sense of what is possible in certain time frames?
Okay, so you have research experience, and that will obviously help you. But have you had to work alone to produce 80,000 words before, that are original, peer-reviewed? Whilst attending conferences, and trying to publish? I'm sure you are a capable researcher, but the PhD is a specific piece of research, with specific requirements.