Knowing combat in the MA, I suspect the OP has neglected to flesh out completly under what circumstances his real observation comes from. Or what truely motivated this effort. By offering his admiration of the G6 and F4U-1A in the same line, he is making a gaff of what is really on his mind. The two fighters are not similare enough that you can move from one to the other seamlessly.
I suspect a more relavent answer to his question is the name of a top F4U-1A teacher rather than trying to answer the question: why does the F4U-1A excellerate like a dumptruck compaired to the Bf109-G6.
At face value in a post questioning the speed performance of the F4U-1A there is no purpose to mentioning the Bf109-G6. The comparison is like Chevy trucks to Camero's. Both can do 100mph getting there at different rates in a straight away. The truck can even carry a bit a weight and still get just close to 100mph eventualy.
Many places out there on the internet only give the speed at alt for WW2 fighters along with information shining the best light possible on them. Most neglect to point out that the tests in conneticut and patuxent that achived 380-400 near sea level were with cleaned up airframes. The perk on the F4U-4 is not that high if he wants to fly an F4U that feels as fast as a 109.