I'm going over the NASA TT rules (I'm still HPDE but looking to move into TT at some point), and they have specific dyno settings for horsepower ratings. Time Trial classes are based on a adjusted weight/HP ratio.

NASA TT rule book has the following specifics for Dyno testing:
RWD must use a Dynojet model.
SAE J1349 Rev JUN 90 correction shall be used, along with a smoothing factor of five (5).
Tires inflated to normal track operating pressure (to be as close as possible to post-competition dyno testing).

Would you be able to share your Dynojet settings so that others can use it for comparisons? The images show the smoothing factor, but I'm curious about the correction specification. Depending on these results and other modification factors, the RCF straddles the line between TT2 & TT3. So it can be very competitive (TT3) or be at the bottom end of the class (TT2).