Twin TorqStorm 440 Build

Must the the boost is(was) that high at the hit was because of the dual blowers?

I thought the attraction of the centrifugal blower was the lesser boost at the lower rpms...... and then increase with rpm.
Like, 3-4psi at the beginning of the pull........then be up at some substantially higher number at the end of the pull.

If the belt slippage hadn’t been an issue on this combo, what was the predicted/expected boost supposed to be......at let’s say....... 6000 rpm?