Oh, tech is easy. Just make some tech that mimics the functions of what the psionics would do. Perhaps a tachyon-infusion capacitor, to permanently bestow superhumanly accelerated capabilities (speed, reflexes, recovery, metabolism, etc.) or a mental temporality decelerator (they see it slower, they move faster).
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)