[C and W Racing]

Super comp is a .4 tenths pro tree with an index of 8.90
Super gas is a .4 tenths pro tree with an index of 9.90
Super street is a .5 tenths pro tree with an index of 10.90

If you run one of those classes, you need to be able to run your index no matter what the conditions are. You need to have enough power to be able to run under your index, and how you slow it down to reach your index is with the use of throttle stops and timer's. That type of racing produces some of the closest races of any given event. Stand at the finish line and watch.
Over the years, people have gone to bigger and bigger engines, and because of that, they are on the throttle stop for longer periods of time.
The reason they have done that, is so the entire race is in front of them, the other car and the finish line. Its easier to make decisions on what to do at the finish line if you have everything in front of you, instead of looking over your shoulder to find the other car and loosing sight of the finish line.
You can run door cars in super comp. You just can't run dragsters in the other two classes.
I hope this explains it for you
Chuck