More rollout will make the car ET and 60' slightly quicker because you have a "running start" , so to speak. Reaction times will be slower all else being equal because you have a longer distance to go before leaving the beams. This is why it is critical to stage the car exactly the same every time when bracket racing.
So if you have a DONK you better leave on the top bulb.
I got treed on that one.
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