Why Is It?

Same approach to performance. Assemble engine. Race it. Desire 5 tenths quicker. Buy more performance parts. Try again. Want 2 tenths quicker? Buy more performance parts. All the while leaving a full second on the table by not taking the time to tune, and think through the actual first assembly. They get there, just 2000 dollars later in "more performance parts" :D
You're a tried and true example of tuning to the nth degree. I'd like to see what you could do on a higher budget.