There are no restrictions on accepting IRA funds for purchasing directly owned real estate, allowing you to raise up to 100% of your funds from pension funds.
However, if you invest in non-real estate assets or securities in others’ real estate offerings where you don’t have direct control, exceeding 25% of your investments from pension funds will require compliance with ERISA laws, which can be burdensome.
Returns on IRA investments are taxed based on the leverage property percentage. To understand the implications for IRA investors, research UBIT or UBTI online, as many Self Directed IRA Custodians have written articles about it.
Lastly using your own IRA funds in a syndicate where you hold a management position may be a prohibited transaction.