Graves Motorsports Yamaha R1 FZ1 Velocity Stack Kit. The Graves Motorsports YZF-R1 and FZ-1 Velocity Stack Kit is specially designed to suit the new fuel injected Yamaha Motor.The kit of 4 injection molded plastic intake stacks mount directly into the stock airbox without modification and is designed to smooth out the power curve, increase horsepower throughout and improve fuel efficiency. Power gains of 4 HP in the mid range and 2 HP at the top end are to be expected. For increased result combine with a Dynojet Power Commander and Graves Motorsports exhaust system to maximize your Yamaha R1 or FZ-1 horsepower.Fitment: Yamaha R1 2004-2006 + Yamaha FZ-1 2006-2016