Groan...why do people insist on throwing horsepower figures around. First, the figures mentioned are flywheel or crank not wheel horsepower. Second, the Z has 1 more turbo and 2 more cylinders. My guess is the Z will make much more torque than the STI. And last, the Z has a far greater potential to make power than the STI. A cat back, intake, and chip, and you're looking at 500 (flywheel) horsepower. I've personally seen a stock 96 Z race a new STI, no contest, not evev close, granted, anything can happen on the street adn a lot of times it boils down to the driver. I never have to worry though, I have both a new WRX and a 95 Z-28 (dynoed at 425 rwhp) and I have yet to be taken on the street.