Try actually driving an endurance race.
I did a 24 hour carting race in the mid 90s (twin engine 4 stroke jobbies) at Clay Pidgeon. I was too big really, and didn't have the speed on the straights, but the excess weight helped in the corners, I had more downforce and therefore more grip, so could corner faster than the others. They could only really get me on the long straights, in the tight technical parts, they were losing too much time in the corners to get me on the straights.
But after only a few hours of driving, I was pretty shattered. ISTR we did fairly well for a complete amateur team with a 2nd hand card and none of the drivers had competed in an endurance race before - mid-field somewhere.
