The Golf R does feature all wheel drive so these numbers would drop and likely to under 400 providing the run was on an all wheel drive Dynojet. It was run on a two wheel drive Dynojet so USP unplugged the Haldex all wheel drive module essentially turning the Golf into a front wheel drive car. That does not change the fact this is some serious horsepower and torque over stock and coming from APR you know the reliability will be as close to OEM as a Golf R pushing around 500 crank horsepower can be.
Very nice results for a turbo kit that costs $5924.99 and has been very well tested and tuned. Dyno video below.