Its really hard to say due to tyres suspension engine mounts which play a huge role at this sort of power, not to mention the driver.
You could try those bhp to weight calculators online for a therorical figure but its dependent on traction/mapping.
40-50mph onwards in mine was where it really came into its own, very little could keep up.
Some tuners can map these set ups now to limit the torque in the first couple of gears if 0-60s important.