Most of the uses for an SDIRA surround an active business use for the funds. You have to set up a C-Corp and invest your rolled over SDIRA funds into the C-Corp's private company stock. Now you are a stock holder. With that, you can still pay yourself a salary for running or working at that company that your SDIRA now holds as an investment. So, to cut to the chase, you can make money (through W-2 income, not in the traditional passive income fashion that is associated with most RE) if it's a business expense.
Now, onto real estate investing with those funds. I think you could legitimately use your SDIRA to buy land and have someone plant trees and have them harvested every 10 years, you could invest in a syndication where someone else manages the properties, or you might be able to get away with buying a self-storage and getting paid a reasonable salary to run it. So there are ways to make money from an SDIRA, but only investing in syndiations is truly passive, but you can't take a salary or get paid without a penalty until you are of retirement age. I would say talk to your roll-over specialists, but you might be able to pay yourself for managing a real estate business (as previously mentioned, self-storage comes immediately to mind).
For an example (not really real estate related but I'm hoping it helps a little), I was looking at buying a business with SDIRA by jumping through the necessary hoops ($5K and $130/mo maintenance fee). Then I would work there and get paid a W-2 income. Profits could then get rolled back into the business as seen fit. However, once you've made a $1 in your business, your business is welcome to invest that dollar anyway it sees fit. The term the specialist used was secondary investment. So you're allowed to invest in passive investments with the income you've generated from the business. I thought this was an interesting point. I don't know if you can make income today with that passive investment or manage it yourself, (I'm guessing no and yes, respectively) with the secondary investment, but it's a question you could ask a specialist if you got to that point.
I love this idea in that you find a good, cheap business that throws off cash and you use it to invest in real estate assets. You pay yourself with the business and the real estate assets make you a bunch of money upon retirement and grow tax free until you retire. It's like a 1031 without having to exchange.
The experts out there are free to chastise or correct me as I think it's great to discuss options for this money if you're planning on quitting your day job prior to age 65 (or is it 67, or is it 67.5? Whatever). I recently quit my day job and honestly a 401k is doing me absolutely no good between now and 65/67/67.5! ha! So I'm exploring ways to make that money work harder for me and provide some sort of monthly income.