Were you running on a chassis dyno?
And if so was it a Dyno Dynamics or another brand?
If it was a Dyno Dynamics (in shoot out mode) then we can compare it to our club's dyno day results.
Also, what gear did you run in?
1:1 is 4th gear for the 5 speed gearbox and 5th gear for the 6 speed gearbox.
Running in other gears will mean lower or higher results (for comparative purposes).
On our last
Club Dyno Day most of the normally aspirated NB8s were making between 72 to 82 rwkw (depending on modifications).
So
YES, 61.3 rwkw does sound a little low (if the circumstances indicated above are similar).