I am no expert, but, does a 1001 HP W16 rocket mill not improve on the Veyron's power to weight ratios, theys making its weight vs. power great. Remember, the Veyron is a small two seater rear engined supercar with a massive engine, AWD, and extremely good drag coeficient... Its built for speed... So weight was an issue.
As in, I am not disputing your case. I just need to get more info.
Did they build that monster out of steel only? Or is it using carbon fibre wood, etc like the Z06 or Enzo?
1001ps mill certainly helps power/weight ratio, acceleration and top speed.
The thing is, VW boss had a wet dream of 400kmh car, and for this particular goal 4200 lbs car is just as good as 3500lbs. They could made it lighter, going RWD, manual, with smaller engine (Hennessey Viper 1000 comes to mind), but they choose not to.
Veyron doesn't have extremely good drag coefficient. Even at special speed-mode it's still quite a brick -
0.36.
GT-R have 0.27.
CdA for Veyron is 8.02, worser than Z06 or GT-R.
My guess is designers and marketing dep, not engineers, were given upper hand on this behemoth.
Weight does effect top speed by increasing rolling resistance as the tire flexes.
As I said it's possible, but not necessarily - depends on the tire compound/structure and pressure.