Just watched the formula-regional-european-championship race at Monaco.
I think they are 290bhp, and laptimes of around 1:30.
Barring any change to the track in the interim - that compares to the F1 times of 1969? I would expect them to equal cars of a later year - even though they had over 400bhp.
Have to say - great racing, and probably more appropriate to the Monaco circuit (along with historic F-1) than the current regulation.