If like me you occasionally watch formula 1 and think it doesn't look that fast, this video from Spa showing speed comparison through Eau Rouge clearly demonstrates the actual difference...
https://www.youtube.com/watch?v=K2cNqaPSHv0
And this is with overlap
https://www.youtube.com/watch?v=Ex5dhhpSHCw
Kind of puts everything into perspective really
cheers...Nige