I've won more than my share of N/SS races. That meant foot brake and no electronics. The ability to keep accurate data is one element. The ability to use that data to dial the car in a few days of changing weather and track conditions is another. We were usually able to keep the car with-in .01 of the index (10.50). If the track was very poor we'd back of to 11.0. Learn those two things,cut a consistent light,drive the finish line, add some luck and you'll be set.
Doug