In a test like that weight is always going to be the problem.
Extra weight increases braking distance, brake life (Have you seen how thick an F1 brake pad is??) etc... not to mention an F1 car uses slick tyres.
If an F1 car where to be set up for a top speed run, ie gearbox had taller ratios, and downforce was wound off, I think an F1 car could come close to the Veyron - I think an F1 car would be closer to the top speed of the Veyron, than the Veyron would get to an F1 car on a twisty track due to the expense that has gone in to an F1 car to ensure is maximun versitility for its application
