The Internet is full of GT86/BRZ engine mods and swaps, from simple turbos to full Supra transplants. This is the the most exciting so far though. Easily.
It's a GT86 with a 750hp 5.8-litre NASCAR engine. Conveniently enough the engine is from Toyota Racing Developments so it's even kept in the family. The car was built a couple of years ago for the Japanese Formula D series and it is - as you would hope - hilariously sideways.
That, combined with the outrageous noise and proper development mule look, makes this a very cool GT86. It's a nicely shot film too, with the proviso that you will have to read some subtitles.