I don't know all the details about that Supra, but yes it has about 500rwkw, and it has an auto transmission, and drag tyres which I don't have. I never expected to win that race haha.
One thing that people often forget, is that it's not just about the peak power, it's about the area under the whole power curve. The Supra would have significantly more power at low RPM due to the larger capacity of a 2JZ. The result of this (combined with the drag tyres and different gear ratios) is clearly evident in the video when the Supra gets ahead of my MR2 in the first half of the race.
If you watch closely towards the end of the race, the gap hardly increases at all because at that point it's all down to the power-to-weight ratio at peak power, which is very similar in both cars.