resistance level in workout mode

[skorbuly]

hi John,
I tried an FTP workout yesterday.
in workout mode there is no grades, you just fight with watts and cadence.
my problem is I can reach only 420W on 50/12 gears with 130 cadence.
I think I'm on resistance level 1., that's because I can't reach more watts.
how could I raise my iflow's resistance level in workout mode?
Should I edit the power_calc_factors_imagic.txt?
regards