going by horsepower per liter, the toyota gr yaris has one of the most powerful production engines currently on the market. its 1.6-liter turbocharged inline-three is rated at an incredible 268 horsepower straight from the factory. while that sounds incredibly high-strung, it seems the engine has a whole lot more left on the table, even with mostly stock internals.
motive garage and and powertune australia wanted to see just how far they could push the gr yaris's tiny three-cylinder before cracking it open to swap out things like cams, pistons, and rods, upgrading everything from the turbo to the maf sensor to the fueling system. the only real mechanical update within the engine is new valve springs. with everything maxed out, the team was able to squeeze an incredible 473 hp to the wheels on a hub dyno.
that number makes it the most powerful gr yaris on the planet (that we know of, anyway). the tuners have yet to test the car at the drag strip, but expect it to munch the quarter-mile in the 10-second range and eclipse a 130-mph trap speed.
from: road & track