To my mind, it’s not about suspension vs karts, or street tires vs race tires; you don’t drive frames or suspension, you manage energy flow, tire loads, rotation, etc, all of which happen whether you have suspension or not. So really, it’s about your mental driving process, and to TJ’s point, how much of your current KK performance level is built on a rock solid understanding of driving that has adequate breadth and depth, and how much is built on rote, or hyper-rehearsing. I suspect much of your performance is based on the latter <sorry, I meant to say former>, but that would be good to confirm.
Also, just FYI, if you are talking about the iSpeed app for iRacing, that has been out of development for several years, so the number of drivers on that reflect a small portion of the actual user community. Also, the FR2.0 class is pretty small compared to the Skip Barber class (last season there were 4,713 FR2.0 drivers compared to 15,103 SB drivers with many 8-10 year veteran
s)
Lastly, weather conditions can have a huge impact on lap times, for example in the Skip Barber series, lap times can vary 2+ seconds just from weather.
The best way to see how you stack up compared to the greatest quantity of high-level drivers would be to get the Skip Barber car, and do the Time Trials competition each week (if you have that week’s track). TTs are run in set weather conditions for everyone, and you can look at your results compared to all SB drivers who have done TTs that week.
Anyway, the bottom line is doing some iRacing (TT, wheel-to-wheel, or both), could provide the opportunity to evaluate your current performance level in a new environment, and hopefully increase the breadth and/or depth of your skill set.
BTW, I’m not affiliated with iRacing in any way.