The surprise is that the Drift Mustang held it's own despite it's limitations...

Race cars are built for the track, so it's no surprise that an American Iron Mustang is going to be faster than Vaughn Gittin Jr's drift car. Race cars, though, are always built with restrictions, so how much faster can it be? As we find out in this highly scientific video, while the Carl's Junior-bashing drifter is busy sliding through a turn, Chris Cobetto in the racer is maximizing traction and powering out. On Summit Point's straights, though, it's Gittin Jr and his unrestricted motor that take off.
Dunno how scientific it is. All race cars are restricted and the drift 'stang was not. Also, on a wider racetrack, he wouldn't have been able to block the turns like that.

Drift Mustang vs. Race-car Mustang Story