But next time i got a spit16 barreling down on me, i'll make sure to PM him and tell him his spit isent capable of doing that. because the "charts" say so 
Imagine this, if you will.
A Ferrari sits at a stop light. Behind him, an old beat-up Ford pickup truck comes barreling down the road at 60mph. The light turns green as the truck arrives, and it blazes on through without ever stopping. Sure, the Ferrari can accelerate to 60mph in mere seconds, but at this point the Ford is already hundreds of feet ahead before the Ferrari can match and exceed its speed. Ultimately, the Ferrari will pass the Ford, but it's not an instant thing - even if he is going significantly faster.
See where I'm going here?
If you're flying level in a P-51, and a Spit XVI dives down on you, he's going to be a lot faster than you. Your plane's top speed might be greater, but at that moment
your speed relative to his is lower. It's going to take time to match his speed by trying to dive away, and then it's going to take more time still for you to pull away once you exceed his speed. During all of that, you're vulnerable.