Find a track that hasn't changed much in years. Watkins glen maybe? and compare historic lap times to those from today. what I've noticed is tire technology as made most of the improvements in lap time possible if not directly responsible for them. they (some historic racing show/series on speed) had some historic cars on modern rubber a few years back. and the cars were still in the same race trim, and some of their original drivers were behind the wheels. the lap times were much lower, and the drivers kept mentioning how the brakes were wearing out so much faster as they could actually use them now when 30 years ago they would lock the tires if used too much. but the power and acceleration was still brutal, that was the same.