Viper Days is really several events in one.
First is the driving school. Run what you bring. Figure 2 days with several hours of driving each day. It's good to make sure you car is ready to "exercise" for a couple of days so have it checked before you come ... have plenty of brake pad, good fluids etc. Great support if you do wear something out from the Archers; Bobby and Tommy.
Second the Challenge Series. Same as above but you get points as well, and people look at the matrix to find which class they participate in. Kumhos would put ya in unlimited I believe. The series is sponsored by Michelin after all.
Third the Racing League. Race prepared cars running side by side. Great racing as either a final destination or prep for other series. Many folks in other professional series raced and still race there.
I've personally found everyone to be really helpful and having a lot of fun. Please feel free to PM if you have any questions. Or call Courtney for all the real, official answers.
Cheers,
Jim